If the average of z and x is 35, and the average of x and y is 25, then z-y=?
A
5
B
10
C
20
D
30
Correct Answer: 20
Hints: শর্তমতে, (z + x)/2 = 35 z + x = 70 (x + y)/2 = 25 x + y = 50 z + x - x - y = 70 - 50 z - y = 20