Question

Write which number or alphabet in sequence replaces the question mark(?).

7, 15, 32, 67. 138, ?

• A. 193
• B. 209
• C. 278
• D. 281

Answer 1

The correct option is D 281

The given sequence follow a pattern :

$7\times 2+1=15$,

$15\times 2+2=32$,

$32\times 2+3=67$,

$67\times 2+4=138$

Similarly, $138\times 2+5=281$.

Hence, $281$ replaces question mark.