Question

3/5 of sweets are red
and the rest are blue.
Write the ratio blue to red.

Answer 1

If 3/5 of sweets are red, the remaining sweets represent the

$1-\dfrac{3}{5}=\dfrac{5}{5}-\dfrac{3}{5}=\dfrac{2}{5}$

of the total. So, 3/5 are red and 2/5 are blue.

The blue to red ratio is

$\dfrac{2}{5}\div\dfrac{3}{5}=\dfrac{2}{5}\cdot\dfrac{5}{3}=\dfrac{2}{3}$