Question

A number, x, equals 80% of the average of 5, 7, 14 and a number y. If the average of x and y is 26, then value of y is:

• A. 13
• B. 26
• C. 39
• D. 42
• E. None of these

Answer 1

The correct option is C 39

Average of 5, 7, 14 and $y=\frac{5+7+14+y}{4}$
Therefore, $x=80\%of\frac{5+7+14+y}{4}=\frac{80}{100}\times \frac{26+y}{4}$
$\Rightarrow x=\frac{26+y}{5}\left(1\right)$
Also $\frac{x+y}{2}=26\left(2\right)$
From (1) and (2), we get $52-y=\frac{26+y}{5}\Rightarrow y=39$