CBSE Questions for Class 12 Commerce Applied Mathematics Linear Equations Quiz 9 - MCQExams.com

Solve the following pair of linear equations by the substitution method
$$s-t=3, \dfrac {s}{3}+\dfrac {t}{2}=6$$
  • $$s = 2, t = 7$$
  • $$s = 9, t = 6$$
  • $$s = 3, t = 1$$
  • $$s = 6, t = -9$$
Solve the following pair of linear equations by the substitution method
$$x + y = 14, x - y = 4$$
  • $$x = 8, y = 5$$
  • $$x = 6, y = 9$$
  • $$x = 7, y = 10$$
  • None of these
Solve the following pair of linear equations by the substitution method.
$$0.2x + 0.3y = 1.3, 0.4x + 0.5y = 2.3$$
  • $$x=1, y=-2$$
  • $$x=6, y=-7$$
  • $$x=5, y=1$$
  • $$x=2, y=3$$
The sum of the numerator and denominator of a fraction is $$4$$ more than twice the numerator. If the numerator and denominator are increased by $$3$$, they are in the ratio $$2 : 3$$. Determine the fraction
  • $$\dfrac {1}{7}$$
  • $$\dfrac {2}{5}$$
  • $$\dfrac {3}{7}$$
  • $$\dfrac {5}{9}$$
Form the pair of linear equations for the following problem and find their solution by substitution method.
The larger of two supplementary angles exceeds the smaller by $$18$$ degrees. 
  • $$x + y = 100$$ and $$x - y = 18$$,  $$x=90$$ and $$\,y=16$$
  • $$x + y = 60$$ and $$x - y = 18$$,  $$x=95$$ and $$\,\,y=70$$
  • $$x + y = 180$$ and $$x - y = 18$$,  $$x=99$$ and $$\,\,y=81$$
  • None of these
A lending library has a fixed charge for the first three days and an additional charge for each day thereafter. Saritha paid Rs. $$27$$ for a book kept for seven days, while Susy paid Rs. $$21$$ for the book she kept for five days. Find the fixed charge and the charge for each extra day.
  • Fixed charge: Rs. $$12$$, Charge for each extra day: Rs. $$9$$
  • Fixed charge: Rs. $$15$$, Charge for each extra day: Rs. $$3$$
  • Fixed charge: Rs. $$18$$, Charge for each extra day: Rs. $$3$$
  • Data insufficient
The taxi charges in a city consist of a fixed charge together with the charge for the distance covered. For a distance of 10 km, the charge paid is Rs. 105 and for a journey of 15 km, the charge paid is Rs.What are the fixed charges and the charge per kilometer? How much does a person have to pay for traveling a distance of 25 km?
  • Fixed charge is Rs.$$5$$ and the charge per kilometer is Rs.$$10$$ For $$25$$ km person have to pay Rs.$$255$$.
  • Fixed charge is Rs.$$10$$. and the charge per kilometer is Rs.$$5$$. For $$25$$ km person have to pay Rs$$135$$.
  • Fixed charge is  Rs. $$15$$  and the charge per kilometer is  Rs. $$5$$. For $$25$$ km person have to pay Rs.$$140$$.
  • Fixed charge is 
    Rs.$$50$$. and the charge per kilometer is Rs$$20$$. For $$25$$ km person have to pay Rs$$50$$
Form the pair of linear equations in the following problems, and find their solutions (if they exist) by the elimination method:
Meena went to a bank to withdraw Rs. $$2000.$$ She asked the cashier to give her Rs. $$50$$ and Rs. $$100$$ notes only. Meena got $$25$$ notes in all. Find how many notes of Rs. $$50$$  and Rs. $$100$$  she received
  • $$15$$  notes of Rs. $$50$$  and $$18$$  notes of Rs. $$100.$$
  • $$12$$  notes of Rs. $$50$$  and $$18$$ notes of Rs. $$100$$.
  • $$8$$ notes of Rs. $$50$$ and $$25$$  notes of Rs. $$100.$$
  • $$10$$ notes of Rs. $$50$$ and $$15$$ notes of Rs. $$100$$.
Rs. 58 is divided among 150 children such that each girl gets 25p and each boy get 50p. How many boys are there ?
  • $$52$$
  • $$54$$
  • $$68$$
  • $$62$$
A fraction becomes $$\dfrac {9}{11}$$, if $$2$$ is added to both the numerator and the denominator. If $$3$$ is added to both the numerator and the denominator it becomes $$\dfrac {5}{6}$$. Find the fraction.
  • $$\dfrac{7}{9}$$
  • $$\dfrac{5}{7}$$
  • $$\dfrac{9}{11}$$
  • None of these
Form the pair of linear equations in the following problem, and find their solutions (if they exist) by the elimination method:
The sum of the digits of a two-digit number is $$9$$. Also, nine times this number is twice the number obtained by reversing the order of the digits. Find the number.
  • Number is $$18$$
  • Number is $$36$$
  • Number is $$81$$
  • None of these
Five years hence, the age of jacob will be three times that of his son. Five years ago, Jacob's age was seven times that of his son. What are their present ages?
  • Present age of Jacob: $$50$$ years and Present age of Jacob's son: $$15$$ years
  • Present age of Jacob: $$50$$. years and Present age of Jacob's son: $$10$$ years
  • Present age of Jacob: $$40$$ years and Present age of Jacob's son: $$10$$ years
  • Present age of Jacob: $$35$$  years and Present age of Jacob's son: $$15$$ years
Two years ago, a father was five times as old as his son. Two years later, his age will be $$8$$ more than $$3$$ times the age of the son. Find the present age of father.
  • $$22$$ years
  • $$60$$ years
  • $$39$$ years
  • $$42$$  years
Form the pair of linear equations in the following problems, and find their solutions (if they exist) by the elimination method:
Five years ago Nuri was thrice as old as Sonu. Ten years later, Nuri will be twice as old as Sonu. How old are Nuri and Sonu?
  • Nuri is $$40$$ years old and Sonu is$$ 10 $$years old.
  • Nuri is $$50$$ years old and Sonu is$$ 20$$ years old.
  • Nuri is $$70$$  years old and Sonu is $$30$$ years old.
  • Nuri is $$60$$ years old and Sonu is $$10$$ years old.
The sum of the digits of a two-digit number is $$5$$. The digit obtained by increasing the digit in tens' place by unity is one-eighth of the number. Then the number is
  • less than $$30$$
  • lies between $$30$$ and $$40$$
  • more than $$37$$
  • lies between $$40$$ and $$50$$
A fraction becomes $$\dfrac  {1}{3}$$ when $$1$$ is subtracted from the numerator and it becomes $$\dfrac  {1}{4}$$ when $$8$$ is added to its denominator. Find the fraction.
  • $$\dfrac{1}{4}$$
  • $$\dfrac{4}{17}$$
  • $$\dfrac{5}{12}$$
  • None of these
The difference between two numbers is $$ 7$$  and their sum is $$35$$. What will be their product?
  • $$324$$
  • $$294$$
  • $$79$$
  • $$245$$
If $$\displaystyle \frac{x+y}{x-y}=\frac{5}{3}\: and\: \frac{x}{\left ( y+2 \right )}=2$$ the value of (x , y) is
  • (4, 1)
  • (2, 8)
  • (1, 4)
  • (8, 2)
Sum of two numbers is $$35$$ and their difference is $$13$$. Then the numbers are
  • $$10, 25$$
  • $$22, 13$$
  • $$24, 11$$
  • $$20, 15$$
In covering a distance of $$30$$ km, Abhay takes $$2$$ hours more than Sameer. If Abhay doubles his speed, then he would take $$1$$ hour less than Sameer. What is Abhay's speed? (in km/hr)
  • $$2$$
  • $$3$$
  • $$4$$
  • $$5$$
If Rs. $$50$$ is distributed amount $$150$$ children giving $$50$$ p to each boy and $$25$$ p to each girl. Then the number of boys is 
  • $$25$$
  • $$40$$
  • $$36$$
  • $$50$$
The electricity bill of a certain establishment is partly fixed and partly varies as the number of units of electricity consumed. When in a certain month 540 units are consumed, the bill is Rs.In another month 620 units are consumed and the bill is Rs.In yet another month 500 units are consumed then, the bill for that month would be 
  • Rs. 1560
  • Rs. 1680
  • Rs. 1840
  • Rs. 1950
Albert buys $$4$$ horses and $$9$$ cows for Rs. $$13400$$. If he sells the horses at $$10\%$$ profit and the cows at $$20\%$$ profit, then he earns a total profit of Rs. $$1880$$. The cost of a horse is
  • Rs. $$1000$$
  • Rs. $$2000$$
  • Rs. $$2500$$
  • Rs. $$3000$$
The real numbers $$x$$ and $$y$$ are such that $$\displaystyle x+\frac{2}{y}=\frac{8}{3}$$ and $$\displaystyle y+\frac{2}{x}=3$$ . 
The value of $$xy$$, is 
  • $$\displaystyle \frac{4}{3}$$
  • $$\displaystyle \frac{16}{9}$$
  • $$2$$
  • $$4$$
Mr. Joshi has $$430$$ cabbage-plants which he wants to plant out. Some $$25$$ to a row and the rest $$20$$ to a row. If there are to be $$18$$ rows in all how many rows of $$25$$ will there be?
  • $$10$$
  • $$14$$
  • $$8$$
  • $$12$$
If $$\displaystyle r+s=t$$ and $$\displaystyle x+t=y-2s$$, then which of the following must be true ?
  • $$\displaystyle r+2s-x=y-t$$
  • $$\displaystyle r+2s-t=x+y$$
  • $$\displaystyle x+r=y+s$$
  • $$\displaystyle x+r=y-3s$$
10 years ago the age of the father was 5 times that of the son. 20 years hence the age of the father will be twice that of the son. The present age of the father (in years) is
  • $$40$$
  • $$45$$
  • $$60$$
  • $$70$$
What values of x and y satisfies the equations  $$\displaystyle \frac{x}{6}+\frac{y}{15}=4$$ and $$\displaystyle \frac{x}{3}-\frac{y}{12}=4\frac{3}{4}$$
  • $$(6,15)$$
  • $$(18,15)$$
  • $$(15,18)$$
  • $$(12,30)$$
A certain two digits number is equal to five times the sum of its digits. If $$9$$ were added to the number, its digits would be reversed. The sum of the digits of the number is:
  • $$6$$
  • $$7$$
  • $$8$$
  • $$9$$
The father's age is six times his son's age. Four years hence, the age of the father will be four times his son's age. The present ages, in years, of the son and the father are respectively,
  • $$4$$ and $$24$$
  • $$5$$ and $$30$$
  • $$6$$ and $$36$$
  • $$3$$ and $$24$$
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Practice Class 12 Commerce Applied Mathematics Quiz Questions and Answers