Practice MCQ Questions and Answer on Series Completion
51.
One term in the number series is wrong. Find out the wrong term.
2, 3, 4, 4, 6, 8, 9, 12, 16
(A) 3
(B) 6
(C) 9
(D) 12
Solution:
The given sequence is a combination of three series: I. 1st, 4th, 7th terms i.e. 2, 4, 9,..... II. 2nd, 5th, 8th terms i.e. 3, 6, 12,..... III. 3rd, 6th, 9th terms i.e. 4, 8, 16,..... In each one of I, II and III, each term is twice the preceding term. So, 9 is wrong and must be replaced by (4 x 2) i.e. 8.
52.
Choose the missing terms out of the given alternatives : A, G, L, P, S ?
(A) U
(B) W
(C) X
(D) Y
Solution:
A + 6 = G + 5 = L + 4 = P + 3 = S + 2 = U
53.
2, 2, 5,13, 28, ?
(A) 49
(B) 50
(C) 51
(D) 52
Solution:
The pattern is + 0, + 3, + 8, + 15, ..... i.e. + (l2 - 1), + (22 - 1), + (32 - 1), + (42 - 1), ..... So, missing term = 28 + (52 - 1) = 28 + 24 = 52.
54.
3, 15, ?, 63, 99, 143
(A) 27
(B) 35
(C) 45
(D) 56
Solution:
The terms of the given series are (22 - 1), (42 - 1),....., (82 - 1), (102 - 1), (122 - 1). So, missing term = (62 - 1) - (36 - 1) = 35.
55.
One term in the number series is wrong. Find out the wrong term.
1, 2, 4, 8, 16, 32, 64, 96
(A) 4
(B) 32
(C) 64
(D) 96
Solution:
Each term of the series is obtained by multiplying the preceding term by 2. So, 96 is wrong and must be replaced by (64 x 2) i.e. 128.
56.
4, 9, 25, ?, 121, 169, 289, 361
(A) 49
(B) 64
(C) 81
(D) 87
Solution:
The given series consists of squares of consecutive prime numbers i.e. 22, 32, 52,....., 112, 132, 172, 192. So, missing term = 72 = 49.
57.
4832, 5840, 6848, ?
(A) 7815
(B) 7846
(C) 7856
(D) 7887
Solution:
The pattern is + 1008. So, missing term - 6848 + 1008 = 7856.
58.
One term in the number series is wrong. Find out the wrong term.
2, 5, 10, 50, 500, 5000
(A) 5
(B) 10
(C) 50
(D) 5000
Solution:
Each term of the series is the product of the preceding two terms. So, 5000 is wrong and must be replaced by (50 x 500) i.e. 25000.
59.
Choose the missing terms out of the given alternatives.
T, R, P, N, L, ?, ?
(A) J, G
(B) J, H
(C) K, H
(D) K, I
60.
66, 36, 18, ?
(A) 3
(B) 6
(C) 8
(D) 9
Solution:
Each term in the series is the product of the digits of the preceding term. So, missing term = 1 x 8 = 8.