The average of 20, 70 and x is 40. If the average of 20, 70, x and y is 50, then y=?
A
100
B
80
C
70
D
60
Correct Answer: 80
20 + 70 + x = 3 × 40 বা, x = 30 20 + 70 + 30 + y = 200 বা, y = 80