Question

she adds 3/10 of a fluid ounce of red to 11/15 of a fluid ounce of blue to make 1 1/30 fluid ounces of purple. How many fluid ounces of red paint will she need to make 3 fluid ounces of purple paint?

Answer 1

Answer:

.9 ounces

Step-by-step explanation:

We need to find the common denominator so we can more easily add the paint amounts together.

3/10  red                 11/15 blue  common denominator is 30

3*3 / 10*3                11*2/15*2

9/30                        22/30

To get purple we add

9/30 + 22/30  = 31/30 or 1 1/30 ounces

Now let's find how much we need for 3 ounces of purple.

If the purple is 30% red paint (3/10 or .3) and 70% blue paint (11/15 or .7)

So we take .3 * 3 = .9

30% of 3 ounces is .9 ounces, so she will need .9 or 27/30 ounces.