To make purple paint you must mix 2 parts blue with 5
parts red. If I use 13 cups of
blue, how much red would I
need for the same shade of
purple?

32.5 cups of red

Step-by-step explanation:

Lets take it step-by-step.

So to make purple paint you mix 2 parts of blue and 5 parts of red. So if you use 13 cups of blue you need to use 32.5 cups of red because...

13 divided by 2 = 6 1/2, so you would have to multiply 5 x 6 1/2 which is 32.5

Next time you come across a problem like this take the large number you have Ex. 13, and divide it by the smaller number you know Ex. 2, and then multiply the number that you've gotten by dividing Ex. 6 1/2, with the other small number Ex. 5, and then you have your answer.

If you need any more help let me know :)

correct answers below:

i think the answer is seven, for if i'm being useless °ω°

step-by-step explanation: