Question

What number should be, added to each term of the ratio 3:5 to make the ratio 4 : 5?.

Answer 1

Let $x$ be the required added number

$\therefore$ $\frac{3+x}{5+x}=\frac{4}{5}$

$5(3+x)=4(5+x)$

$\Rightarrow$ $15+5x=20+4x$

$\Rightarrow$ $x=5$