Qus: Look at this series: 21, 9, 21, 11, 21, 13, 21, ... What number should come next?

Qusइस श्रंखला को देखें: 21, 9, 21, 11, 21, 13, 21, ... आगे कौन सी संख्या आनी चाहिए?

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A. 14
B. 15
C. 21
D. 23

Solution

B. 15

Explanation

In this alternating repetition series, the random number 21 is interpolated every other number into an otherwise simple addition series that increases by 2, beginning with the number 9.