Question

In a class the number of students is 84, If there where six boys more and six girls less, then the ratio of boys and girls is 5: 2. Find the number of boys in the class.

• A. $60$
• B. $30$
• C. $51$
• D. $58$

Answer 1

The correct option is B $30$

Let the number of boys$=x$

Number of girls be $=y$

$x+y=84$ ………$\left(1\right)$

$\frac{x+6}{y-6}=\frac{5}{2}$

$2x+12=5y-30$

$2x-5y=-42$ ………$\left(2\right)$

Solving equation $\left(1\right)$ and $\left(2\right)$

we get

$x=54$

$y=30$.