In following number series, two terms have been put within brackets. Choose the appropriate option
Find out the missing number in the following sequence :1, 3, 3, 6, 7, 9, ?, 12, 21.
Option:
A. 10
B. 11
C. 12
D. 13
Answer: D . 13
Tweet
Justification:
Clearly, the given sequence is a combination of two series :
I. 1, 3, 7, ?, 21 and
II. 3, 6, 9, 12
The pattern followed in I is + 2, + 4, ...; and
the pattern followed in IIis + 3.
Thus, missing number = 7 + 6 = 13.
Hence, the answer is (d).
