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

Answer: Option C

Solution(By Examveda Team)

We have:
$$\eqalign{ & \Rightarrow \left( {\frac{{2 + 7 + 6 + x}}{5}} \right) = 5 \cr & \Rightarrow 15 + x = 20 \cr & \Rightarrow x = 5 \cr} $$
Also,
$$\eqalign{ & \Rightarrow \left( {\frac{{18 + 1 + 6 + x + y}}{5}} \right) = 10 \cr & \Rightarrow 25 + 5 + y = 50 \cr & \Rightarrow y = 20 \cr} $$