Number Series: Aptitude Questions with Answers – Free Practice!
Q. 1 Find the last term: 2, 4, 8, 16, 32, ?
Check Solution
Ans: B
Multiplying by 2 each time: 2*2*2*2*2*2 = 64
Q. 2 Find the last term: 3, 6, 11, 18, 27, ?
Check Solution
Ans: C
Differences are increasing by 2: +3,+5,+7,+9,+11
Q. 3 Find the last term: 121, 144, 169, 196, ?
Check Solution
Ans: A
Series of perfect squares: $11^2,12^2,13^2,14^2,15^2 = 225$
Q. 4 Find the last term: 1, 4, 9, 16, 25, ?
Check Solution
Ans: B
Series of perfect squares: $1^2,2^2,3^2,4^2,5^2 = 25$
Q. 5 Find the last term: 5, 10, 20, 40, ?
Check Solution
Ans: C
Solution: Multiplying by 2: 5×2=10, 10×2=20
Q. 6 Find the last term: 2, 6, 12, 20, 30, ?
Check Solution
Ans: A
Differences are +4,+6,+8,+10,+12
Q. 7 Find the last term: 1, 3, 7, 15, 31, ?
Check Solution
Ans: A
Series is $2^n-1$
$2^1-1 = 1$
$2^2-1 = 3$
$2^3-1 = 7$
$2^4-1 = 15$
$2^5-1 = 31$
$2^6-1 = 63$
Q. 8 Find the last term: 13, 17, 19, 23, 29, ?
Check Solution
Ans: B
Series of prime numbers.
Q. 9 Find the last term: 97, 89, 83, 79, 77, ?
Check Solution
Ans: B
Subtracting successively: -8, -6, -4, -2, -4
Q. 10 Find the last term: 0, 1, 1, 2, 3, 5, 8, ?
Check Solution
Ans: B
Fibonacci series
Q. 11 Find the missing number in the given series:
59.7, 61.5, 65.1, 72.3, ?
Check Solution
Ans: C
61.5 – 59.7 = 1.8 = 1.8 × 1
65.1 – 61.5 = 3.6 = 1.8 × 2
72.3 – 65.1 = 7.2 = 1.8 × 4
86.7 – 72.3 = 14.4 = = 1.8 × 8
∴ Missing number is 86.7.
Q. 12 Direction: What will come in the place of the question mark ‘?’ in the following question?
33, ?, 176, 224, 259, 283.
Check Solution
Ans: B
The series follows the following pattern
33 ? 176 224 259 283
(difference between these numbers are as following )
⇒ 283-259 = 24 = 5×5 – 1
⇒ 259 – 224 = 35 = 6×6 – 1
⇒ 224 – 176 = 48 = 7×7 – 1
The next is 63 = 8×8 – 1
⇒ 176 – 63 = 113
Hence the next term in the series is 113.
Q. 13 What should come in place of the question mark ‘?’ in the following number series?
8, 10, 23, 73, ?
Check Solution
Ans: A
Calculation:
The series follows following pattern:
⇒ 8 × 1 + 2 = 10
⇒ 10 × 2 + 3 = 23
⇒ 23 × 3 + 4 = 73
⇒ 73 × 4 + 5 = 297
∴ The value of ? is 297
Q. 14 What should come in place of the question mark ‘?’ in the following number series?
1005, 1000, 985, 960, 925, ?
Check Solution
Ans: C
Calculation:
The series follows the following pattern:
⇒ 1005 – 5 = 1000
⇒ 1000 – 15 = 985
⇒ 985 – 25 = 960
⇒ 960 – 35 = 925
⇒ 925 – 45 = 880
∴ The value of ? is 880
Q. 15 What will come in the place of the question mark (?) in the following number series?
18, 20, 26, 38, 58, ?
Check Solution
Ans: D
Calculation:
⇒ 18 + 1 x 2 = 20
⇒ 20 + 2 x 3 = 26
⇒ 26 + 3 x 4 = 38
⇒ 38 + 4 x 5 = 58
⇒ 58 + 5 x 6 = 88
Q. 16 Find the missing number in the given series:
12, 7, 8, 13, ?
Check Solution
Ans: C
12 × 0.5 + 1 = 7
7 × 1 + 1 = 8
8 × 1.5 + 1 = 13
13 × 2 + 1 = 27
∴ Missing number is 27.
Q. 17 What should come in place of the question mark ‘?’ in the following number series?
0.25, 2.25, 6.25, 12.25, 20.25, ?
Check Solution
Ans: B
The series follows the following pattern:
0.5 × 0.5 = 0.25
1.5 × 1.5 = 2.25
2.5 × 2.5 = 6.25
3.5 × 3.5 = 12.25
4.5 × 4.5 = 20.25
5.5 × 5.5 = 30.25
Q. 18 In each of the following number series, a wrong number is given. Find out that number.
18, 34, 66, 130, 262, 514
Check Solution
Ans: C
The series follows the following pattern:
18 × 2 – 2 = 34
34 × 2 – 2 = 66
66 × 2 – 2 = 130
130 × 2 – 2 = 258
258 × 2 – 2 = 514
∴ The wrong term in the series is 262.
Q. 19 What should come in place of the question mark ‘?’ in the following number series?
600, 590, 610, 580, 620, ?
Check Solution
Ans: B
The series follows the following pattern:
600 – 10 = 590
590 + 20 = 610
610 – 30 = 580
580 + 40 = 620
620 – 50 = 570
∴ The next term in the series is 570
Q. 20 What should come in place of ‘?’ in the following number series?
11, 15, 21, 29, 39, ?
Check Solution
Ans: B
The given series is following the given pattern:
11 + 4 = 15
⇒ 15 + 6 = 21
⇒ 21 + 8 = 29
⇒ 29 + 10 = 39
⇒ 39 + 12 = 51
∴ 51 is the required number.
Improve Aptitude with LearnTheta’s AI Practice
Adaptive Practice | Real Time Insights | Resume your Progress
Next Topic Simplification
Refer Thousands of Quantitative Aptitude Questions with Answers and Detailed Solutions