Be My Multiple I Will Be Your Factor - Class 5 Maths - Extra Questions

The product of two numbers is $$882$$ and their LCM is $$126$$. What is the HCF of these numbers?

Given that:
Product of two numbers$$=882$$
$$LCM$$ of the same numbers$$=126$$
$$HCF=?$$

Since we know that,
$$HCF\times LCM=$$ Product of the numbers
$$HCF\times 126=882$$
$$HCF=\dfrac{882}{126}$$

$$HCF=7$$.

Hence, the HCF is $$7$$.


Find four common multiples of $$8$$ and $$12$$.

To find common multiples, we need to calculate $$LCM$$ of both numbers,
Factors of both numbers are as follows:
$$8=2\times2\times2$$
$$12=2\times2\times3$$

Hence, $$LCM=2\times2\times2\times3$$

$$=24$$

Multiples of $$24$$ will be common multiples of $$8$$ and $$12$$.

Hence, four common multiples of $$8$$ and $$12$$ are $$24, \ 48,\ 72$$ and $$96.$$ 


What is $$L.C.M$$

$$LCM$$ stands for least common multiple. The $$LCM$$ of two numbers is the smallest number that they both divide evenly into.
For example- $$LCM$$ of $$2$$ and $$3$$ is $$6$$.



Write the first ten multiples of $$6$$ and $$8$$.Circle their common multiples.

Multiples of $$6\rightarrow 6, 12, 18, 24, 30, 36, 42, \underline{48}, 54, 60$$
Multiples of $$8\rightarrow 3, 16, \underline{24}, 32, 40, \underline{48}, 56, 64, 72, 80$$
Common multiples of $$6$$ and $$8, 24, 48$$


Write the prime factors of $$120$$

Factors of $$120=2\times 2\times 2\times 3\times 5$$
Prime factors $$=\left\{2,\,3,\,5\right\}$$


Give two examples of a number which is divisible by:
(a) $$3$$ but not $$9$$     (b) $$2$$ but not $$6$$.

a) Two numbers which are divisible by $$3$$ but not by $$9$$ are $$3,6$$.
b) Two numbers which are divisible by $$2$$ but not by $$6$$ are $$2,4$$.


Find the following:
$$(i)$$ the first $$15$$ multiples of $$8$$.
$$(ii)$$ the first $$40$$ positive integers divisible by $$(a)\,3\,(b)\,5\,(c)\,6$$

$$(i)$$ Multiples of $$8, \quad 8,16,24....8n$$
Where $$n\epsilon I,n\epsilon [1,15]$$
$$(ii) (a)$$ Multiples of $$3\quad 3,6,9....3n$$
Where $$n\epsilon I,n\epsilon[1,40]$$
$$(b)$$ Multiples of $$5,\quad 5,10,15...5n$$
Where $$n\epsilon I,n\epsilon[1,40]$$
$$(c)$$ Multiples of $$6,\quad 6,12,18,24....6n$$
Where $$n\epsilon I,n\epsilon [1,40]$$


Write down all the factors of the following number
$$75$$

$$75 = 1 \times 75$$
$$75 = 3 \times 25$$
$$75 = 5 \times 15$$
Hence the factors are $$1, 3, 5, 15, 25$$ and $$75$$


Write the first six multiples of : 
$$4$$

Following are the first six multiples of $$ 4 $$
$$ 1 \times 4 = 4 $$ 
$$ 2 \times 4 = 8 $$ 
$$ 3 \times 4 = 12 $$ 
$$ 4 \times 4 = 16 $$ 
$$ 5 \times 4 = 20 $$ 
$$ 6 \times 4 = 24 $$ 
Hence multiples of $$ 4 $$ are $$ 4 , 8 , 12 , 16 , 20 $$ and $$ 24 $$ 


Fill in the blanks :
Every number is a multiple of .............

Every number is a multiple of itself


Fill in the blanks :
$$x$$ is a factor of $$y$$ , then $$y$$ is a ........... of $$x$$ .

$$x$$ is a factor of $$y$$ , then $$y$$ is a multiple of $$x$$


Write the first six multiples of : 
$$11$$

Following are the six multiples of $$ 11 $$ 
$$ 1 \times 11 = 11 $$ 
$$ 2 \times 11 = 22 $$ 
$$ 3 \times 11 = 33 $$ 
$$ 4 \times 11 = 44 $$ 
$$ 5 \times 11 = 55 $$ 
$$ 6 \times 11 = 66 $$ 
Hence, multiples of $$ 11 $$ are $$ 11 , 22 , 33 , 44 , 55 $$ and $$ 66 $$ 


Here are factor trees of the number $$ 90 $$. Write the missing numbers:
1789090_061d1b262e2c4a958034a9f712c64d98.png

Factor tree of $$90$$ : $$ 5 \times 3 \times 3 \times 2 $$ 

1752223_1789090_ans_59778c6954ec46fdae564635e5ca8d6a.png


Write the first six multiples of : 
$$9$$

Following are the first six multiples of $$ 9 $$ 
$$ 1 \times 9 = 9 $$ 
$$ 2  \times 9 = 18 $$ 
$$ 3  \times 9 = 27 $$ 
$$ 4  \times 9 = 36 $$ 
$$ 5  \times 9 = 45 $$ 
$$ 6  \times 9 = 54 $$ 
Hence required multiples of $$ 9 $$ are $$ 9 , 18 , 27 , 36 , 45 $$ and $$ 54 $$ 


Write the first six multiples of : 
$$16$$

Following are the first six multiples of $$ 16 $$
$$ 1 \times 16 = 16 $$ 
$$ 2 \times 16 = 32 $$ 
$$ 3 \times 16 = 48 $$ 
$$ 4 \times 16 = 64 $$ 
$$ 5 \times 16 = 80 $$ 
$$ 6 \times 16 = 96 $$ 
Hence , multiples of $$ 16 $$ are $$ 16 , 32 , 48 , 64 , 80 $$ and $$ 96 $$ 


Write the first six multiples of : 
$$ 15 $$ 

Following are the first six multiples of $$ 15 $$ 
$$ 1 \times 15 = 15 $$ 
$$ 2 \times 15 = 30 $$ 
$$ 3 \times 15 = 45 $$ 
$$ 4 \times 15 = 60 $$ 
$$ 5 \times 15 = 75 $$
$$6\times 15=90$$ 
Hence , multiples of $$ 15 $$ are $$ 15 , 30 , 45 , 60 , 75 $$ and $$ 90 $$ 


Determine the prime factorisation of the following positive integer:
(i) $$20570$$ (ii) $$58500$$ (iii) $$45470971$$


$$20570=2^1\times5^2\times 11^2\times17 \quad\quad\quad$$$$58500={ 2 }^{ 2 }\times { 3 }^{ 2 }\times { 5 }^{ 3 }\times { 13 }^{ 1 }\quad \quad \quad 45470971={ 7 }^{ 2 }\times { 13 }^{ 2 }\times { 17 }^{ 2 }\times { 19 }^{ 1 }$$

1225648_964538_ans_3f913389777b497da529257a432072ef.png


Find the LCM and HCF of the following integers by applying the prime factorisation method.
(i) $$12, 15$$ and $$21$$ (ii) $$17, 23$$ and $$29$$ (iii) $$8, 9$$ and $$25$$

Using prime factorisation method:

(i) 12, 15 and 21

Factor of $$12 = 2 \times 2 \times 3$$

Factor of $$15 = 3 \times 5$$

Factor of $$21 = 3 \times 7$$

HCF $$(12, 15, 21) = 3$$

LCM $$(12, 15, 21) = 2 \times 2 \times 3 \times 5 \times 7 = 420$$

(ii) 17, 23 and 29

Factor of $$17 = 1 \times 17$$

Factor of $$23 = 1 \times 23$$

Factor of $$29 = 1 \times 29$$

HCF $$(17, 23, 29) = 1$$

LCM $$(17, 23, 29) = 1 \times 17 \times 23 \times 29 = 11,339$$

(iii) 8, 9 and 25

Factor of $$8 = 2 \times 2 \times 2 \times 1$$

Factor of $$9 = 3 \times 3 \times 1$$

Factor of $$25 = 5 \times 5 \times 1$$

HCF $$(8, 9, 25) = 1$$

LCM $$(8, 9, 25) = 2 \times 2 \times 2 \times 3 \times 3 \times 5 \times 5 = 1,800$$


Test each of the following numbers for divisibility by i)3 ii)5 and iii)9.
a. 5049              b. 7705              c. 4265
d. 6990              d. 45350            e. 2391
g. 1475               h. 46299             i. 775


1698444_1026612_ans_4e868ddef1a2415eb21438385e195e4a.jpg


Write the smallest $$5$$ digit number. Express it in terms of its prime factor by a tree diagram.

We know that,

The smallest five-digit number is $$10000.$$

Prime factor of $$10000=2\times 2\times 2\times 2\times 5\times 5\times 5\times 5$$


1016799_1085165_ans_172321a1697b4998a7cf6c9f2b01cf5b.png


Write all the numbers less than $$100$$ which are common multiples of $$3$$ and $$4$$.

The multiples of 3 less than $$100$$ are $$3,6,9,12,15,18,21,24,27,30,33,36,39,42,45,48,51,54,57,60,63,66,69,72,75,78,81,84,87,90,93,96,99$$

multiples of 4 less than $$100$$ are $$4,8,12,16,20,24,28,32,36,40,44,48,52,56,60,64,68,72,76,80,84,88,92,96,100$$

Therefore, the common multiples less than $$100$$ are $$12, 24, 36, 48, 60, 72, 84, 96$$


Find first three common multiples of :
a) $$6$$ and $$8$$
b) $$12$$ and $$18$$

A) The multiples of $$6$$ are $$0,6,12,18,24,30,36,42,48,...$$

The multiples of $$8$$ are $$0,8,16,24,32,40,48,56,64,...$$

Therefore, the first three common multiples are $$0,24,48$$

B) The multiples of $$12$$ are $$0,12,24,36,48,60,72,84,96,108,120,132,144,156,168,...$$

The multiples of $$18$$ are $$0,18,36,54,72,90,108,126,144,162,180,198,216,234,252,,...$$

Therefore, the first three common multiples are $$0,36,72$$



Write the first five multiples of $$10$$ and $$20$$. Highlight their common multiple and find their LCM.

Multiples of $$10$$:
$$10, \textbf{20}, 30, \textbf{40}, 50$$
Multiples of $$20$$
$$\textbf{20}, \textbf{40}, 60, 80, 100$$
Common multiples of $$10$$ and $$20$$ are $$20, 40$$

To find $$\text{LCM}$$ of $$20$$ and $$40$$, we need to write these numbers in the form of product of their prime factors:

$$20=2\times 2\times 5=2^2\times 5$$
$$40=2\times 2\times 2\times 5=2^3\times 5$$
$$\text{LCM(20,40)}=2\times 2\times 2\times 5$$
                        $$=40$$ Ans


Define multiple. Give four examples.

Multiple-It is a number which when multiplied with another number produces a given number.
For example- 
1. 30 is a multiple of 6 as 6×5=30
2. 45 is  a multiple of 5 as 5×9=45
3. 21 is a multiple of 7 as 7×3=21
4. 39 is a multiple of 13 as 13×3=39


Write first five multiplies of the following number.
$$25$$.


1504343_1658805_ans_45dabb4fbda44117ac39a901026e62ba.jpg


Write the prime factorisations of $$16, 28, 38$$.

$$16=2\times2\times2\times2$$
$$28=2\times2\times2$$
$$38=2\times19$$
Prime factor $$16=2^4$$
Prime factor $$28=2^2\times 7$$
Prime factor $$38=2\times19$$


Write first five multiplies of the following number.
$$35$$.

To find first 5 multiples of 35,
35×1=35
35×2=70
35×3=105
35×4=140
35×5=175
So, the first 5 multiples of 35 are 35,70,105,140 and 175


Find first three common multiples of $$12$$ and $$18$$.

$${\textbf{Step 1: Find multiples of 12 and 18.}}$$

                $${\text{Multiples of 12 are}} = 12,24,36,48,60,72,84,96,108,120,132,144,.....$$

                $${\text{Multiples of 18 are}} = 18,36,54,{\text{72,90,108,126,144,162,....}}$$

$${\textbf{Step 3: Find common multiples}}$$

                $${\text{First three common multiples are: }}36,72,108$$  

$${\textbf{First three common multiples of 12 and 18 are: }}\mathbf{36,72,108.}$$



Write first five multiplies of the following number.
$$40$$.


1503460_1658808_ans_209f166d20cc44f0bdb09c6f714a1f1b.PNG


Write all prime numbers between $$40$$ and $$85$$.


1502692_1658834_ans_5f385613a94c46d59caafdee308d45d2.PNG


Here is different factor tree for $$60$$. Writ the missing number.

1658965_5e0c48934a1844959231df0f6c7f0214.png

So $$3, 2$$ are in the blanks.
1517808_1658965_ans_6df30ef0aa564f01b648bda630220406.png


Find first two common multiplies of $$12$$ and $$18$$.


1504675_1658828_ans_39e666cbd9bd4edc84a5b5d445c8d78a.jpg


Factorize the following algebraic expression.
$$5(x-2y)^2+3(x-2y)$$.


1686900_1673500_ans_ec75faf98cb44606952f0839375bf1cb.jpg


Factorize the following algebraic expression.
$$3a(x-2y)-b(x-2y)$$.


1686910_1673505_ans_bf5b502bcace4902871673d979e278af.jpg


Prove that $$\dfrac {1}{9!}+\dfrac {1}{10!}+\dfrac {1}{11!}=\dfrac {122}{11!}$$


1407568_1666360_ans_f7f31b097ed2483fb4f86c57366900e4.jpg


Here is different factor trees for $$60$$. Write the missing number.
1658968_2d9a5a9c40ce44b2ba2a215696b3eb9f.png


1504907_1658968_ans_d19ce404548940a7bf937cf57a2517a8.png


Fill in the blank.
If the product of two numbers is $$360$$ and their HCF is $$6$$, then their LCM is _______.

The problem can be solved using the property that product of two numbers is equal to the product of HCF and LCM.
Using the above mentioned property:
$$HCF\times LCM =360$$
$$LCM\times 6=360$$
$$LCM=\dfrac{360}{6}$$
$$LCM =60$$
Hence, the LCM is $$60$$.


Factorize the following algebraic expression.
$$9a(6a-5b)-12a^2(6a-5b)$$.


1686897_1673498_ans_1a98b212e1114c9497682c71611d5fb0.jpg


Factorize the following algebraic expression.
$$6(a+2b)-4(a+2b)^2$$.


1686946_1673510_ans_c913cd78bdf74a1085ddd089b122645f.jpg


Factorize the following algebraic expression.
$$2r(y-x)+s(x-y)$$.


1686887_1673494_ans_7d4fb8dc18ed48d2a6618063831721d0.jpg


Factorize the following algebraic expression.
$$a(x-y)+2b(y-x)+c(x-y)^2$$.


1686951_1673514_ans_0f0b23f158be4988b5e45993a9757474.jpg


Factorize the following algebraic expression.
$$4(x+y)(3a-b)+6(x+y)(2b-3a)$$.


1686972_1673520_ans_0b92b7f31b70462d9807e244d5c67047.jpg


Factorize the following expression.
$$p^2q-pr^2-pq+r^2$$.


1686985_1673525_ans_e302c85c2f6448b5833b2488ed20031b.jpg


Factorize the following expression.
$$36l^2-(m+n)^2$$.


1693984_1673606_ans_b5b1a5ee1e6f4db78df66e5c8311f4d9.jpg


Factorize the following expression.
$$3a^5-48a^3$$.


1693976_1673602_ans_03abd1affd3a459fa268a4099e9a9e64.jpg


Factorize the following expression.
$$(x+2y)^2-4(2x-y)^2$$.


1693975_1673601_ans_0580b5f5477f4be591e3ec2faad2f755.jpg


Factorize the following algebraic expression.
$$(2x-3y)(a+b)+(3x-2y)(a+b)$$.


1686957_1673518_ans_2d32dc7db6684575adbce13a1fd6e05a.jpg


Factorize the following expression.
$$144a^2-169b^2$$.


1693970_1673598_ans_a81af20b8a034b38badc20f0c647e769.jpg


Factorize the following expression.
$$125x^2-45y^2$$.


1693968_1673596_ans_745eb02319ef4b128dab5275aac5842f.jpg


Factorize the following expression.
$$x^3-144x$$.


1693989_1673621_ans_4dd2b6e04e4a484ab9cf5929ad81e17c.jpg


Factorize the following expression.
$$12m^2-27$$.


1693967_1673594_ans_7a6d1e819ba04f64895d2f381a0ff932.jpg


Factorize the following algebraic expression.
$$p^2q^2-6pqr+9r^2$$.


1694048_1673692_ans_09f4b83dfde34e22899497efb57d661d.jpg


Factorize the following algebraic expression.
$$36a^2+36a+9$$.


1588622_1673693_ans_9297142b7e454252999754fc0d15e116.jpg


Factorize the following expression.
$$(x+y)^2-(a-b)^2$$.


1693995_1673627_ans_f7786737585b4995a7c49d8ae4b3a613.jpg


Factorize the following expression.
$$\dfrac{1}{16}x^2y^2-\dfrac{4}{49}y^2z^2$$.


1693997_1673628_ans_86dfcce14611438c8f522961464a072d.jpg


Factorize the following algebraic expression.
$$9a^2-24ab+16b^2$$.


1694046_1673689_ans_4426c72027b94e0bbe17c07aec4f429d.jpg


Factorize the following algebraic expression.
$$16-a^6+4a^3b^3-4b^6$$.


1588630_1673699_ans_834288a83e3742b2a2388d9954a68fe3.jpg


Factorize the following algebraic expression.
$$a^2-2ab+b^2-c^2$$.


1588632_1673702_ans_5b76e534c7cc4f75b219d41e7e865437.jpg


Factorize the following algebraic expression.
$$x^2+2x+1-9y^2$$.


1588637_1673703_ans_36dcc2dcd7ba4ff487c1e648a6373a1d.jpg


Factorize the following algebraic expression.
$$a^2+2ab+b^2-16$$.


1588624_1673694_ans_49efc84a0b7b48d3ad590bc6c0083245.jpg


Factorize the following algebraic expression.
$$9z^2-x^2+4xy-4y^2$$.


1588626_1673696_ans_1366c38b06584d25bf61fa7d3fe2d733.jpg


Factorize the following algebraic expression.
$$x^2+9y^2-6xy-25a^2$$.


1588645_1673719_ans_dd1f4583308149c29ef28161a3b9da67.jpg


Factorize the following algebraic expression.
$$a^2+4ab+3b^2$$.


1588638_1673705_ans_3dec7d049b9d4c9ab484342b4018a259.jpg


Factorize the following algebraic expression.
$$96-4x-x^2$$.


1539513_1673706_ans_4bb2b1e13e9640c48c0b634251868c3d.jpg


Factorize the following algebraic expression.
$$4x^4+1$$.


1588639_1673710_ans_895243f53da14346860d99dba38258ab.jpg


Factorize the following algebraic expression.
$$(x+2)^2-6(x+2)+9$$.


1539520_1673715_ans_aca0c59464c54fbeaae267beca14e5aa.jpg


Factorize the following algebraic expression.
$$a^2-8ab+16b^2-25c^2$$.


1588651_1673724_ans_f246448164b04e009618c9a90692b728.jpg


Factorize the following algebraic expression.
$$25-p^2-q^2-2pq$$.


1588644_1673717_ans_760ee8115c364c428b3e615aeb4ecaa4.jpg


Express 360 as product of its prime factors.

$$360=3\times 120$$
      $$=3\times 3\times 40$$
      $$=3\times 3\times 2\times 20$$
      $$=3\times 3\times 2\times 2\times 10$$
      $$=3\times 3\times 2\times 2\times 2\times 5$$ 


Find the least multipliers of the number 3675, 4374, 18375, 74088 respectively, which will make the product perfect squares.


1573962_1745430_ans_2c7641130be749ba9a3106df53619bab.png


Find the least multipliers of the numbers 7623, 109350, 539539 respectively, which will make the product perfect cubes.


1573966_1745431_ans_dfc8d5a37a4e46d28c82af00b8b7718e.png


Here are factor trees of the number $$ 90 $$. Write the missing numbers:
1789084_ad88eee12e9f4049a62c1ca8db4a6f18.png

Factor tree : $$ 90 = 2 \times 5 \times 3 \times 3 $$  
1752225_1789084_ans_12fad3da56c74963ad73ea5c3ac253d8.png


Write the first five multiples of the following number
$$23$$

$$23 \times 1 = 23$$
$$23 \times 2 = 46$$
$$23 \times 3 = 69$$
$$23 \times 4 = 92$$
$$23 \times 5 = 115$$
$$\therefore$$ The five multiples of $$23$$ are $$23, 46, 69, 92$$ and $$115$$


If $$P$$ is prime number then, what is the LCM of $$P, \ P^2, \ P^3$$?


1805425_1784879_ans_169a142ac27e481881a662b8ca3fee77.png


Write the first five multiples of the following number
$$70$$

$$70 \times 1 = 70$$
$$70 \times 2 = 140$$
$$70 \times 3 = 210$$
$$70 \times 4 = 280$$
$$70 \times 5 = 350$$
$$\therefore$$ The first five factors are $$70, 140, 210, 280$$ and $$350$$


Write the first five multiples of the following number:
$$17$$

$$17 \times 1 = 17$$
$$17 \times 2 = 34$$
$$17 \times 3 = 51$$
$$17 \times 4 = 68$$
$$17 \times 5 = 85$$
$$\therefore$$ The first five multiples of $$17$$ are $$17, 34, 51, 68$$ and $$85$$


express each of the following numbers as a product of its prime factors: $$5005$$


1789069_1814319_ans_85cc31d7e0ad4dd9b12ed8e25ca1effa.png


Find the $$LCM$$ of $$80,96,125,160$$ 

Find the factors of $$80,96,125,160$$,
The Factors of $$80,96,125$$ and $$160$$
$$=2\times 2\times 2\times 2\times 2\times 3\times 5\times 5\times 5$$
Hence the $$LCM$$ of $$80,96,125$$ and $$160$$
$$=2\times 2\times 2\times 2\times 2\times 3\times 5\times 5\times 5=12000$$
1643804_1788968_ans_c44c79b604594477911cabf4d0d63135.png


Write the first five multiples of the following number
$$65$$

$$65 \times 1 = 65$$
$$65 \times 2 = 130$$
$$65 \times 3 = 195$$
$$65 \times 4 = 260$$
$$65 \times 5 = 325$$
$$\therefore$$ The first five multiples of $$65$$ are $$65, 130, 195, 260$$ and $$325$$


Write first six multiples of the following natural numbers :
$$ 3 $$ 

$$ 3 $$ 
The first six multiple of $$ 3 $$ are 
$$ 3 , 6 , 9 , 12 , 15 , 18 $$ 


Find the $$LCM$$ of $$160,170$$ and $$90$$.

$$\textbf{LCM of numbers can be found by multiplying all the prime factors of the numbers, but by}$$
$$\textbf{considering the common factors of the numbers  only once}$$.

Prime factorization of the number 
$$160 = 2 \times 2 \times 2 \times 2 \times 2 \times 5$$
$$170 = 2 \times 5 \times 17$$
  $$90 = 2 \times 3 \times 3 \times 5$$

$$\therefore$$  LCM $$= 2 \times 2 \times 2 \times 2 \times 2 \times 3 \times 3 \times 5 \times 17$$
             $$ = 24480$$

$$\textbf{Hence, the LCM of 160, 170, 90 is 24480}$$


Find the highest power of $$5$$ in $$23750$$.

To find the highest power of $$5$$ in $$23750$$, we have to factorize $$23750$$.
1789079_1814337_ans_440e4d4af5b046ef914bf725847caa6a.PNG


Express each of the following numbers as a product of its prime factors: $$32760$$.


1789072_1814324_ans_64e2b5c265064f90b3a2119199b26dfd.PNG


Express each of the following numbers as a product of its prime factors: $$156$$.


1789073_1814327_ans_54786240c5ae4a15b2f45b65c97230cc.png


Write down the missing numbers $$a,b,c,d,x,y$$ in the above factor tree.

1814389_469ff0cccb274a3182f95693c3fb4e70.png


1789102_1814389_ans_b6abad3fbb794a00bafbd346fe57cb9e.png


Write down the missing numbers $$a,b,c,d,x,y$$ in the above factor tree:

1814403_048acc313c234dfd90568fe7c3d8012c.png


1789423_1814403_ans_32a4d59d811943a0ae382c775bd94d22.png


Find the highest power of $$2$$ in $$1440$$.

Given number is $$1440$$
Factorization of $$1440$$ is

1789081_1814366_ans_2814d27a2bb24671895e0de775cb35a8.PNG


Write down the missing numbers $$a,b,c,d,x,y$$ in the above factor tree:

1814393_f971b8b39be34df0b6a1fed0d40ca55a.png


1789104_1814393_ans_adc14982fa174c1e800b1267bc721d1e.png


Using the common multiple method, find the L.C.M. of the following:
$$10, 15$$ and $$20$$

$$10, 15$$ and $$20$$
2            10          15            20
2            5            15            10
3             5           15             5
5             5            5              5
                1              1              1
We get,
$$L.C.M = 2 × 2 × 3 × 5$$
$$ = 60$$
Hence, $$L.C.M.$$ of $$10, 15$$ and $$20 = 60$$


Write down the missing numbers $$a,b,c,d,x,y$$ in the above factor tree:

1814399_57db8bd898374a8eb10e69900e1a8e2b.png


1789379_1814399_ans_73456ec11b6045f0be18d71f3f7c3aea.png


Express each of the following numbers as a product of its prime factors: $$729$$.


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Using the common multiple method, find the L.C.M. of the following:
$$3, 6, 9$$ and $$12$$

$$3, 6, 9$$ and $$12$$
2       3,     6,       9,       12
2       3,      3,       9,       6
3        3,      3,       9,      3
3        1,       1,        3,       1
           1,       1,        1,        1
We get,
$$L.C.M. = 2 × 2 × 3 × 3$$
$$ = 36$$
Hence, $$L.C.M.$$ of $$3, 6, 9$$ and $$12 = 36$$


Here are two different factor trees for $$ 60 $$ write the missing numbers.
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Write first $$ 10 $$ number which are common multiples of $$ 3 $$ and $$ 4 $$

Multiples of $$ 3=3,6,0,12,15,18,21,24,27,30 $$
Multiples of $$ 4= 4,8,12,16,20,24,28,32,36,40 $$
Common multiples= $$ 12,24,36,48,60,72,84,96 $$


Find the value of a in the factor tree.
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$$2 \times 5 = 10$$
$$10 \times 2 = 20$$
$$20 \times 5 = 100$$
∴ $$a= 100$$


Factorize the following algebraic expression.
$$-4(x-2y)^2+8(x-2y)$$.


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Factorize the following algebraic expression.
$$4x^4+y^4$$.


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Class 5 Maths Extra Questions