Question

The ratio of boys and girls in a class is 5:3. 20% the boys and 60% of the girls have passed in class. What percentage of the class has passed in first class?

Answer 1

Let the number of boys and girls be $5x$ and $3x$.

Number of those who are passed in first class

$=20$%$of5x+60$%$of3x$

$=(\frac{20}{100}\times 5x)+(\frac{60}{100}\times 3x)$

$=x+\frac{9x}{5}$

$=\frac{14x}{5}$

Then, required percentage

$=(\frac{14x}{5}\times \frac{1}{(5x+3x)}\times 100)\%$

$=\frac{14x}{5}\times \frac{100}{8x}\%$

$=35\%$