A solution of rubbing alcohol is 75.7 % (v/v) isopropanol in water. How many milliliters of isopropanol are in a 87.7 mL sample of the rubbing alcohol solution?

66.4 mL

Explanation:

A 75.7% (v/v) value, means that for every 100 mL of rubbing alcohol, there are 75.7 mL of isopropanol.

With the above information in mind, we can solve the problem by multiplying 87.7 mL by 75.7 %:

87.7 mL * 75.7 / 100 = 66.4 mL

So there are 66.4 mL of isopropanol in 88.7 mL of rubbing alcohol.