We have that Juan used in total 16 1/3 tubes of paint or else 49/3 tubes of paint for his painting. He also used 5 1/4 ounces of brush cleaner or 21/4 ounces of brush cleaner. We have thus that 21/4 ounces of brush cleaner correspond to 49/3 tubes of paint. Suppose that x ounces of brush cleaner corresponds to 1 tube of paint. The two quantities are proportionate thus the following equation holds:
Hence we have:
This yields that x is equal to
. By dividing both numerator and denominator by 7, we get that the painter need 9/28 ounces of bruch cleaner for every tube of paint (this is equal to 0,32 in decimal system)
Hence we have:
This yields that x is equal to