Jeff Miller

GMAT OFFICIAL GUIDE PS – A glass was filled with 10 ounces of water…

A glass was filled with 10 ounces of water…

Solution:

We are given that 0.01 ounces of water evaporated EACH DAY. Furthermore, we know that this process happened over a 20-DAY PERIOD. To calculate the total amount of water that evaporated during this time frame we need to multiply 0.01 by 20. This gives us:

0.01 x 20 = 0.2 ounces

Finally, we are asked for “What percent” of the original amount of water evaporated during this period. To determine this percentage, we have to make sure we translate the expression correctly. We can translate it to:

(Amount Evaporated/Original Amount) x 100%

(0.2/10) x 100%

(2/100) x 100% = 2%

Answer: D