Number Series Questions and Answers Part-13

1. Find the missing term: 5, 2, 7, 9, 16, 25, ?
a) 41
b) 45
c) 48
d) 52

Answer: a
Explanation: Each term in the series, except the first two terms, is the sum of the preceding two terms.
So, missing term = 16 + 25 = 41

2. Find the missing term: 1, 1, 4, 8, 9, 27, 16, ?
a) 32
b) 64
c) 81
d) 256

Answer: b
Explanation: The series consists of squares and cubes of consecutive natural numbers i.e., 12 , 13, 22 , 23 , 32 , 33 , 42 .................
So, missing term = 43 = 64

3. Find the missing term: 10, 14, 26, 42, 70, ?
a) 100
b) 102
c) 106
d) 114

Answer: d
Explanation: Each term in the series, except the first two terms, is 2 more than the sum of the preceding two terms.
So, missing term = (42 + 70) +2 = 114

4. Find the missing term: 4, 12, 36, 108, ?
a) 144
b) 216
c) 304
d) 324

Answer: d
Explanation: The pattern is × 3
So, missing term = 108 × 3 = 324

5. Find the missing term: 2, 8, 16, 128, ?
a) 2042
b) 2046
c) 2048
d) 2056

Answer: c
Explanation: Each term in the series, except the first two terms, is the product of the preceding two terms.
So, missing term = 16 × 128 = 2048

6. Find the missing term: 3, 4, 7, 7, 13, 13, 21, 22, 31, 34, ?
a) 42
b) 43
c) 51
d) 52

Answer: b
Explanation: The given sequence is a combination of two series:
I. 3, 7, 13, 21, 31, ? and
II. 4, 7, 13, 22, 34
The pattern in I is + 4, + 6, + 8, + 10,......
The pattern in II is + 3, + 6, + 9, + 12,..............
So, missing term = 31 + 12 = 43

7. Find the missing term : 90, 180, 12, 50, 100, 200, ?, 3, 50, 4, 25, 2, 6, 30, 3
a) 150
b) 175
c) 225
d) 250

Answer: a
Explanation: Clearly, 90 = 30 × 3, 180 = 6 × 30, 12 = 2 × 6, 50 = 25 × 2, 100 = 4 × 25, 200 = 50 × 4
So, missing term = 3 × 50 = 150

8. In the series 10, 17, 24, 31, 38,...... which of the following will be a number of the series ?
a) 48
b) 346
c) 574
d) 1003

Answer: b
Explanation: The given series consists of numbers each of which, on dividing by 7, leaves a remainder 3, No other number except 346 satisfies the property.

9. Find the missing term: 13, 32, 24, 43, 35, ?, 46, 65, 57, 76
a) 45
b) 52
c) 54
d) 55

Answer: c
Explanation: The given sequence is a combination of two series:
I. 13, 24, 35, 46, 57 and
II. 32, 43, ?, 65, 76
The pattern in both I and II is + 11
So, missing term = 43 + 11 = 54

10. Find the missing term: 4/9, 9/20, ? , 39/86
a) 17/40
b) 19/42
c) 20/45
d) 29/53

Answer: b
Explanation: The sequence in the numerators is + 5, + 10, + 20, ......and that in the denominators is + 11, + 22, + 44,............
So, the numerator of the missing fraction should be (9 + 10)i.e., 19 and the denominator should be (20 + 22)i.e., 42. Thus, the missing term is 19/42 .