The average of 2, 7, 6 and x is 5 and the average of 18, 1, 6, x and y is 10. What is the value of y?
A
5
B
10
C
20
D
30
Correct Answer: 20
Hints: (2 + 7 + 6 + x) / 4 = 5 15 + x = 20 x = 20 - 15 x = 5 and, (18 + 1 + 6 + x + y)/5 = 10 18 + 1 + 6 + 5 + y = 50 y = 20