Question

Pls solve this question

Answer 1

4

Explanation:

(A+B+C+D) / 4 = 10 .... average=sum/number of item

(A+B+C)/3 = 3D ... average of first 3 (A,B,C) is triple of forth (D)

A+B+C = 9D

(9D+D)/4=10

10D = 40

D = 4