Answer:
66.4 mL
Step-by-step 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.