Processing math: 10%
MCQExams
0:0:1
CBSE
JEE
NTSE
NEET
Practice
Homework
×
CBSE Questions for Class 10 Maths Arithmetic Progressions Quiz 4 - MCQExams.com
CBSE
Class 10 Maths
Arithmetic Progressions
Quiz 4
The sum of 2 + 4 + 6 + 8 + .......... + 80 is :
Report Question
0%
1540
0%
1640
0%
1740
0%
1440
Explanation
Given sequence is:
2
+
4
+
6
+
.
.
.
.
.
.
.
+
80
Here,
a
=
2
,
d
=
4
−
2
=
2
,
a
n
=
80
a
n
=
a
+
(
n
−
1
)
d
⇒
80
=
2
+
(
n
−
1
)
2
⇒
80
=
2
n
⇒
n
=
40
⇒
S
40
=
40
2
{
2
a
+
(
n
−
1
)
d
}
=
20
{
4
+
78
}
=
20
×
82
=
1640
The sum of
2
,
7
,
12
,
.
.
.
.
.
.
.
.
.
.
.
.
.
.
to
10
terms is :
Report Question
0%
240
0%
248
0%
245
0%
250
Explanation
Given series is:
2
+
7
+
12
+
.
.
.
.
.
.
.
.
to
10
terms
Here,
a
=
2
,
d
=
7
−
2
=
5
,
n
=
10
⇒
S
n
=
n
2
{
2
a
+
(
n
−
1
)
d
}
⇒
S
10
=
10
2
{
4
+
45
}
=
5
×
49
=
245
Which term in the
A.P.
5
,
13
,
21
,
.
.
.
is
181
?
Report Question
0%
21
st
0%
22
nd
0%
23
rd
0%
24
th
Explanation
Given sequence is
5
,
13
,
21
,
.
.
.
Given:
a
=
5
,
d
=
8
,
n
t
h
term
=
181
To find:
n
∵
.
\therefore
181
is the
23^{\text{rd}}
term.
If the sum of
n
terms of AP. is
476, l = 20, a = 36
, then
n
is equal to :
Report Question
0%
14
0%
15
0%
16
0%
17
Explanation
Given,
\displaystyle { S }_{ n }=476,l=20,a=36,n=?
We know
\displaystyle { S }_{ n }=\frac { n }{ 2 } \left[ a+l \right]
\Rightarrow \displaystyle 476=\frac { n }{ 2 } \left[ 36+20 \right]
=\dfrac { 56n }{ 2 }
=28n
\Rightarrow \therefore n=\dfrac { 476 }{ 28 } =17
If
\displaystyle a=3,n=20
and
\displaystyle { S }_{ n }=300
, then
l
is :
Report Question
0%
30
0%
25
0%
27
0%
14
Explanation
Given,
a=3, n=20, S_n=300
We need to find
l
\displaystyle { S }_{ n }=\frac { n }{ 2 } \left( a+l \right)
\displaystyle \therefore 300=\frac { 20 }{ 2 } \left( 3+l \right)
\displaystyle \therefore l=27
If numbers
a, b
and
c
are in AP, then
Report Question
0%
\displaystyle b-a=c-b
0%
\displaystyle b+a=c+b
0%
\displaystyle a-c=b-d
0%
None of these
Explanation
Since, given three numbers are in AP, then the common difference will be same.
\therefore
Common difference =
b - a = c - b
The
4^{th}
term of an AP is
14
and its
12^{th}
term is
70
. What is its first term?
Report Question
0%
-10
0%
-7
0%
7
0%
10
Explanation
As we know for an AP with first term
a
and common difference
d
, genral term is
a_n = a+(n-1)d
\therefore \displaystyle a+3d=14
and
\displaystyle a+ 11d=70
On subtracting both the above equations, we get
\displaystyle 8d=56
or
\displaystyle d=7
\displaystyle \therefore \quad a=-7
The sum of
n
natural number is :
Report Question
0%
\displaystyle \frac { n\left( n+1 \right) }{ 2 }
0%
\displaystyle \frac { n(n-1) }{ 2 }
0%
\displaystyle \left( n+2 \right)
0%
\displaystyle \frac { n+1 }{ 2 }
Explanation
As the first
n
natural numbers are
1,2,3,4,5,6,.........n
They form an AP with
a=1
and
d=1
The sum of AP for
n
numbers
=\dfrac{n}{2}(2a+(n-1)d)
=\dfrac{n}{2}(2+n-1)
=\dfrac{n(n+1)}{2}
The
3^{rd}
term of an A.P. is
-40
and
13^{th}
term is zero, then
d
is equal to :
Report Question
0%
-4
0%
4
0%
0
0%
-1
Explanation
Given
3^{rd}
term
=-40
,
13^{th}
term
=0
Now using,
a_n=a+(n-1)d
\therefore \displaystyle { a }_{ 3 }=a+2d=-40
......(i)
and
\displaystyle { a }_{ 13 }=a+12d=0
......(ii)
Subtracting equations (i) and (ii), we get
\displaystyle d=4
If
p, (p - 2)
and
3 p
are in AP, then the value of
p
is
Report Question
0%
-3
0%
-2
0%
3
0%
2
Explanation
Since, given three numbers are in AP, then the common difference between two consecutive terms will be same.
\therefore
\displaystyle (p-2)-p=3p-(p-2)
\Rightarrow -2=2p+2
or
\displaystyle p=-2
The common difference of the
A.P:\;\;5, 3, 1, -1,\dots
is
Report Question
0%
-2
0%
2
0%
-1
0%
3
Explanation
Common difference of an
A.P
is equal to difference between the consecutive terms of the sequence,
d= 3 - 5
= -2
Hence, option
A
is the correct answer.
If
\displaystyle l=20,d=-1,n=17
, then the first term is :
Report Question
0%
30
0%
32
0%
34
0%
36
Explanation
Given
l = 20, d = -1, n = 17
We need to find
a
.
By using
l=a+(n-1)d
\therefore 20=a+(17-1)(-1)
20=a-16
a=20+16
\therefore a=36
50^{th}
term of the AP.
2, 5, 8, 11,.....
is :
Report Question
0%
147
0%
149
0%
151
0%
153
Explanation
Given series
\displaystyle 2,5,8,11,.....
is in A.P.
\therefore \displaystyle a=2,d=3
We need to find
50^{th}
term.
\therefore n=50
\therefore \displaystyle { a }_{ 50 }=a+49d
=2+49\left( 3 \right)
=2+147
=149
Find the sum of the following APs:
-37, -33, -29, .....
to
12
terms
Report Question
0%
-180
0%
180
0%
200
0%
-200
Explanation
Here,
a=-37, d=4
and
n=12
Here we use the formula as given below:
S_n = \dfrac{n}{2}[2a+(n-1)d]
\therefore S_{12}=\dfrac {12}{2}(2\times -37+4\times 11)=6\times -30=-180
Find the sum of the following APs:
2, 7, 12, ......,
to
10
terms
Report Question
0%
245
0%
345
0%
276
0%
250
Explanation
S=\dfrac {n}{2}(2a+d(n-1))
Here,
a=2, d=5
and
n=10
Sum=\dfrac {10}{2}(2(2)+45)
=5\times 49=245
The value obtained by subtracting the
10^{th}
term of an AP from the
17^{th}
term is
56
. Find the common difference.
Report Question
0%
7
0%
16
0%
9
0%
8
Explanation
In an Arithmetic Progression the g
eneral term of an A.P. is given by
T_n
:
\boxed {T_{n} = a+(n-1)d}
According to the statement:
T_{17}-T_{10} = 56
a+(17-1)d-[a+(10-1)d] = 56
a+16d-[a+9d] = 56
a+16d-a-9d = 56
7a = 56
\boxed {d = 8}
The common difference of the sequence
5,8,11,14,
is
Report Question
0%
3
0%
-3
0%
0
0%
1
Explanation
Given,
5,8,11,14
\therefore 8-5=3
11-8=3
14-11=3
The common difference of the sequence
5,8,11,14
is
3
In an AP, the
9th
term is
-72
. The
10th
term is
60
less than the
4th
term. Find the first term of the AP
Report Question
0%
8
0%
-8
0%
-152
0%
10
Explanation
Given that:
a_9=-72
and
a_{10}=a_4-60
Let
a
be the first term and
d
be the common difference then
a+8d=-72
......(1)
And
a+9d=a+3d-60
\Rightarrow 6d=-60\Rightarrow d=-10.
Substituting this value in equation (1), we get
a+8\times (-10)=-72
a=80-72
a=8
Hence,
The first term is
8.
The first term of an AP is
-50
and the
50th
term is
48
. Find the common difference
Report Question
0%
4
0%
1
0%
-3
0%
2
Explanation
Given,
First term
a = -50
50^{th}
term,
T_{50} = 48
d = ?
\boxed {T_{n} = a+(n-1)d}
T_{50} = 48
48 = -50+(50-1)d
48 = -50+49d
49d = 98
\boxed {d = 2}
Find the sum of the following APs:
0.6, 1.7, 2.8, ......
to
100
terms
Report Question
0%
5475
0%
5505
0%
6589
0%
3844
Explanation
Here
a=0.6, d=1.1
and
n=100
As we know,
S_n = \dfrac {n}{2}[2a+(n-1)d]
\therefore S_{100}=\dfrac {100}{2} (2(0.6)+1.1\times 99)=50\times 110.1=5505
In an AP, the
4th
term is
36
. The
21st
term is
108
more than the
9th
term. Find the common difference.
Report Question
0%
12
0%
9
0%
4
0%
-3
Explanation
Given:
T_{4} = 36
T_{21} = 108+T_{9}
d = ?
General term of an A.P.
=T_{n} = a+(n-1)d
T_{21} = 108+T_{9}
a+(21-1)d = 108+a+(9-1)d
20d = 108 +8d
12d = 108
\boxed {d = 9}
Find the common difference in the series: 0.2, 0.9, 1.6 ..............
Report Question
0%
0.5
0%
0.1
0%
0.7
0%
0.6
Explanation
First term,
a_1 = 0.2
Second term,
a_2 = 0.9
Common difference,
d = a_2 - a_1
d= 0.9 - 0.2
\therefore d = 0.7
Find the sum of the arithmetic series
6 + 12 + 18 + ....... 96
.
Report Question
0%
815
0%
816
0%
817
0%
819
Explanation
Given series is
6+12+18+....96
.
Here
a = 6
; last term,
l = 96, d = 12-6 =6
We know that, last term,
l = a + (n - 1) d
\Rightarrow 96 = 6 + (n - 1) 6
\Rightarrow 96 = 6 + 6n - 6
\Rightarrow 96 = 6n
\Rightarrow n = \dfrac{96}{6}
\Rightarrow n = 16
= total number of terms in the series
We know that,
Sum
(S_n) = \dfrac{n}{2}
[First term
+
Last term]
= \dfrac{16}{2} [6 + 96]
= 8 [102]
Therefore,
S_{16} = 816
Find the common difference, if the sum of first n terms will be (n - 2) (n - 1).
Report Question
0%
1
0%
2
0%
3
0%
4
Explanation
The sum of first n terms,
S_n = \dfrac{n}{2} (2a + (n - 1)d)
On comparing the equations, we get
\dfrac{n}{2} (2a + (n - 1) d) = (n - 2)(n + 1)
(2a - d) n + dn^2 = n^2 - n - 2
On comparing the factors of
n^2
, we find the value of
d= 1
\therefore
The common difference is 1.
Find the common difference in the sequence 4, 8, 12, 16, .......... 20
Report Question
0%
8
0%
3
0%
4
0%
2
Explanation
First term,
a_1 = 4
Second term,
a_2 = 8
Common difference,
d = a_2 = a_1
d = 8 - 4 = 4
\therefore
The common difference is 4.
Find the number of terms in an A.P:
-1,\ -5,\ -9,\ ..,\ - 197
Report Question
0%
48
0%
49
0%
50
0%
47
Explanation
Given: AP:
-1, \ -5,\ -9,\ ...,\ -197
Here, First term
a = -1
Common difference
d = a_2 - a_1 = -5 - (-1) = - 4
And last term
a_n = - 197
We know that,
a_n = a + (n - 1) d
\Rightarrow -197 = -1 + (n - 1) - 4
\Rightarrow -197 = -1 - 4n + 4
\Rightarrow -197 + 1 - 4 = -4n
\Rightarrow n = 50
\therefore
There are 50 terms in the A.P
Which term of the
A.P. 2, 9, 16, 23 .............
is
100
?
Report Question
0%
15
0%
10
0%
11
0%
12
Explanation
a = 2
common difference,
d = a_2 - a_1, a - 2 = 7
we know that,
a_n = a + (n - 1) d
a_n = 100
100 = a + (n - 1) 7
100 = 2 + 7n - 7
100 - 2 + 7 = 7n
\dfrac{105}{7} = n
n = 15
Hence,
15th
term of
A.P
. is
100
.
Find 11th term of the A.P. : -3, 1, 5, ........
Report Question
0%
36
0%
37
0%
38
0%
39
Explanation
First term,
a_1 = -3
Common difference,
d = a_2 - a_1 = 1 - (-3) = 4
We know that,
a_n = a_1 + (n - 1) d
a_{11} = - 3 + (11- 1) 4
= -3 + (10) 4
= - 3 + 40
a_{11} = 37
_____ is a list of numbers in which each term is obtained by adding a fixed number to the preceding term except the first term.
Report Question
0%
Geometric value
0%
Geometric series
0%
Arithmetic progression
0%
Arithmetic mean
Explanation
\text {Arithmetic progression}
is a list of numbers in which each term is obtained by adding a fixed number to the preceding term except the first term.
Ex:
1, 2, 3, 4
..... In this sequence, the first number is
1
and the next number is
2
. The difference between the two numbers is
1
and so on.
By adding
1
to the preceding number, we are forming the next term and so on, and the series is in
AP
.
The sum of n terms of an arithmetic sequence can be calculated by .........................
Report Question
0%
S_n = \dfrac{n}{2} [2a+ (n - 1) d]
0%
S_n = \dfrac{n}{2} [2a+ (n + 1) d]
0%
S_n = \dfrac{2n}{2} [2a+ (n - 1) d]
0%
S_n = \dfrac{2n}{2} [2a- (n - 1) d]
Explanation
The sum of n terms of an arithmetic sequence can be calculated by
S_n = \dfrac{n}{2} [2a+ (n - 1) d]
Where, n
denotes the total number of terms
a = first term
d = common difference
S_n
= Sum of n terms
0:0:1
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
0
Answered
1
Not Answered
29
Not Visited
Correct : 0
Incorrect : 0
Report Question
×
What's an issue?
Question is wrong
Answer is wrong
Other Reason
Want to elaborate a bit more? (optional)
Practice Class 10 Maths Quiz Questions and Answers
<
>
Support mcqexams.com by disabling your adblocker.
×
Please disable the adBlock and continue.
Thank you.
Reload page