Question

using the ratio of red:blue=5:6 to make a mixture with 33 cups of blue paint. how many cups of red paint is used?

Answer 1

if the ratio is 5:6 the we know that the sum of them is:

$5+6=11$

and we also know that:

$11\cdot3=33$

so we have to multiply the ratio by 3 so:

$15\colon18$

this means that we need 15 cups of red paint