Find the missing term in the series: 8, 10, 7, 12, 5, 16, 3, ?

A18

B20 ✓ Correct

C24

D19

Correct answer: (B) 20

Explanation

The missing term is 20.

The differences follow primes with alternating signs: +2, -3, +5, -7, +11, -13.

8 + 2 = 10, 10 - 3 = 7, 7 + 5 = 12.

12 - 7 = 5, 5 + 11 = 16, 16 - 13 = 3.

The next prime is 17, so 3 + 17 = 20.

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