The ratio of the number of girls to the number of boys in a school is $$ 2: 5 $$. If the number of boys is $$ 225 $$; find:
(i) the number of girls in the school
(ii) the number of students in the school.
Given
Ratio of girls to the boys in a school $$ = 2.5 $$
Number of boys in a school $$ = 225 $$
(i) Let $$x$$ be the number of girls in a school
Hence number of girls in a school can be calculated as follows:
$$ 2: 5 = x: 225 $$
$$\implies \dfrac {2}{5}=\dfrac{x}{225}$$
$$ \Rightarrow\, 5 \times x = 2 \times 225 $$
$$ \Rightarrow\, x = \dfrac{2 \times 225}{5} $$
$$ \Rightarrow\, x = \dfrac{450}{5} $$
$$ \Rightarrow\, x = 90$$
Therefore the number of girls in the school is $$90$$
(ii) Total number of students in a school becomes
Total student = Total boys + Total girls
$$ = 225 + 90 $$
$$ = 315 $$
Therefore total students in a school are $$31$$