Find the missing number in the sequence: 4, 9, 20, 43, 90, ?

A180

B185 ✓ Correct

C133

D190

Correct answer: (B) 185

Explanation

The missing number is 185.

Each term = previous * 2 + an increasing count.

4*2+1 = 9, 9*2+2 = 20, 20*2+3 = 43.

43*2+4 = 90.

90*2+5 = 185.

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