Question

While working on a large portrait, Juan used 16 1/3 tubes of paint and 5 1/4 ounces of brush cleaner. Juan is visiting an art supply store to get supplies for his next painting. Assuming his next painting requires the same amount of supplies, how many ounces of brush cleaner will he need to buy for every tube of paint?

Answer 1

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:
$\frac{\frac{21}{4}}{\frac{49}{3}} = \frac{x}{1}$
Hence we have:
$\frac{21*3}{49*4}=x$
This yields that x is equal to $\frac{63}{196}$ . 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)