Practice MCQ Questions and Answer on Series Completion
51.
One term in the number series is wrong. Find out the wrong term.
5, 10, 40, 80, 320, 550, 2560
(A) 80
(B) 320
(C) 550
(D) 2560
Solution:
The correct pattern is x 2, x 4, x 2, x 4, ..... So, 550 is wrong and must be replaced by (320 x 2) i.e. 640.
52.
One term in the number series is wrong. Find out the wrong term.
1, 5, 5, 9, 7, 11, 11, 15, 12, 17
(A) 11
(B) 12
(C) 17
(D) 15
Solution:
The given sequence is a combination of two series: I. 1, 5, 7, 11, 12 and II. 5, 9, 11, 15, 17 The pattern in both I and II is + 4, + 2, + 4, + 2. So, 12 is wrong and must be replaced by (11 + 2) i.e. 13.
53.
4, 12, 36, 108, ?
(A) 144
(B) 216
(C) 304
(D) 324
Solution:
The pattern is x 3. So, missing term = 108 x 3 = 324.
54.
Choose the missing terms out of the given alternatives : WFB , TGD , QHG , ?
(A) NIJ
(B) NIK
(C) NJK
(D) OIK
Solution:
1st letter : W - 3 = T - 3 = Q - 3 = N 2nd letter : F + 1 = G + 1 = H + 1 = I 3rd letter : B + 2 = D + 3 = G + 4 = K
55.
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.
56.
Find the term which does not fit into the series: 1CC, 5FU, 9IT, 15LS, 17OR
(A) 5FU
(B) 15LS
(C) 9IT
(D) 17OR
Solution:
1st letter :1 + 4 = 5 + 4 = 9 + 4 = 13 + 4 = 17 2nd letter :C + 3 = F + 3 = I + 3 = L + 3 = O 3rd letter :V - 1 = U - 1 = T - 1 = S - 1 = R Thus, the term 15LS is wrong and must be replaced by 13LS.
57.
13, 35, 57, 79, 911, ?
(A) 1110
(B) 1112
(C) 1113
(D) 1315
Solution:
The terms of the given series are numbers formed by joining together consecutive odd numbers in order i.e. 1 and 3, 3 and 5, 5 and 7, 7 and 9, 9 and 11, ..... So, missing term = number formed by joining 11 and 13 = 1113.
58.
One term in the number series is wrong. Find out the wrong term.
105, 85, 60, 30, 0, - 45, - 90
(A) 105
(B) 60
(C) 0
(D) -45
Solution:
The correct pattern is - 20, - 25, - 30,..... So, 0 is wrong and must be replaced by (30 - 35) i.e. - 5.
59.
1, 9, 25, 49, 81, ?
(A) 100
(B) 112
(C) 121
(D) 144
Solution:
The series consists of squares of consecutive odd numbers i.e. 12, 32, 52, 72, 92,..... So, missing term = 112 = 121.
60.
Choose the missing terms out of the given alternatives.
T, R, P, N, L, ?, ?