# Paint is Red: Blue in a ratio 3:4. If 6 litres of blue is used, how much red?

Aug 3, 2018

$4.5$ liters of red paint.

#### Explanation:

As red and blue paints are n the ratio of $3 : 4$,

for every $4$ liters of blue paint, we need $3$ liters of red paint

this means for every $1$ liter of blue paint, we need $\frac{3}{4}$ liters of red paint

and for $6$ liters of blue paint, we need $\frac{3}{4} \times 6$ liters of red paint

i.e. $\frac{3}{{\cancel{4}}^{2}} \times {\cancel{6}}^{3} = \frac{9}{2} = 4.5$ liters of red paint.