Find the missing number?

A. 13

B. 19

C. 9

D. 21

Answer: Option A

Solution(By Examveda Team)

In each star, the central value equals the sum of the upper and lower digits on each star, subtracting the sum of the left and right hand digits. So,

Missing Number = 9 + 7 + 6 - 5 - 4 = 13.