Final answer:
The painter needs 2.4 ounces of paint thinner to mix with 12 ounces of paint to maintain a 1:5 ratio for the paint mixture.
Step-by-step explanation:
To solve this problem, you can set up a proportion using the ratio given for paint thinner to paint mixture. The ratio is 1 part paint thinner to 5 parts paint mixture. If the painter has 12 ounces of paint, and wants to use all of it in a mixture with the same ratio, we can set up the following proportion:
1 part paint thinner : 5 parts paint
is equivalent to
x parts paint thinner : 12 parts paint
To solve for x (the amount of paint thinner), we can cross-multiply:
1*x = 5*12
x = (5*12)/1
x = 60/1
x = 60
Now we need to remember that x is the total number of parts in this ratio, and we need to find out how many ounces of paint thinner equals 1 part out of 6 total parts (since 1 part thinner plus 5 parts paint equals 6 parts total). So, to find the number of ounces of paint thinner (1 part), we divide the total weight by the total number of parts.
x = 60/6
x = 10
Hence, the painter needs 2.4 ounces of paint thinner for a 12-ounce paint mixture at the same ratio.