Question

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. $10$
• B. $20$
• C. $30$
• D. $18$

Answer 1

Answer: (B)

$20$

Given that average of $2,7,6,x$ is $5$

Therefore, $5=\frac{2+7+6+x}{4}$

$⟹20=15+x$

$⟹x=20-15=5$

Given that average of $18,1,6,x,y$ is $10$

Therefore, $10=\frac{18+1+6+5+y}{5}$ (since, $x=5$)

$50=30+y$

$⟹y=50-30=20$