Question

in a school, average score of girls is 65 and that of boys is 71.if the average of school(boys and girls)is 68 then the ratio of boys to girls is

• A. 2:1
• B. 1:2
• C. 3:1
• D. 1:1

Answer 1

The correct option is D 1:1

$Let\text{the number of boys=x}$
$\text{number of girls=y}$
$\text{The average score of boys =71}$
$\text{total score of boys=71x}$
$\text{The average score of girls =65}$
$\text{total score of girls =65y}$
$\text{total marks of school =71x+65y}....\left(i\right)$
$\text{The average score of school=68}$
$\text{so total marks =68}(x+y)........\left(ii\right)$
$from\left(i\right)and\left(ii\right)$
$71x+65y=68x+68y$
$\Rightarrow 3x=3y$
$\Rightarrow \frac{x}{y}=\frac{1}{1}$
$HenceRatioofboysandgirlsis1:1$