Choose the correct alternative that will continue the same pattern and replace the question mark in the given series.
6, 13,28,59,?
Answer: Option D
Explanation:
The pattern is x 2 + 1, x 2 + 2, x 2 + 3,.....
So, missing term = 59 x 2 + 4 = 122.
4, 12, 36, 108, ?
The pattern is x 3.
So, missing term = 108 x 3 = 324.
Which term of the series 5, 8, 11, 14,.....is 320?
Answer: Option C
Clearly, 5 + 3 = 8, 8 + 3 = 11, 11 + 3 = 14, .....
So, the series is an A.P. in which a - 5 and d = 3.
Let 320 be the nth term of the series.
Then, 320 = 5 + (n - 1) x 3 or (n - 1) = 105 or n = 106.
8, 9, 8, 7, 10, 9, 6, 11, 10, ?, 12
Answer: Option A
The given sequence is a combination of three series :
I. 1st, 4th, 7th, 10th terms i.e. 8, 7, 6, ?
II. 2nd, 5th, 8th, 11th terms i.e. 9, 10, 11, 12
III. 3rd, 6th, 9th terms i.e. 8, 9, 10 The pattern in I is - 1.
So, missing term = 6 - 1 = 5.
3, 7, 15, ?, 63, 127
Answer: Option B
Each number in the series is one more than twice the preceding number.
So, missing term = (15 x 2) + 1 = 31.
