Question

A bowl is half full of water. Four cups of water are then added to the bowl, filling the bowl to 70% of its capacity. How many cups of water are now in the bowl?

• A. 12
• B. 20
• C. 15
• D. 14

Answer 1

The correct option is D 14

If the bowl was already half full of water, then it was originally 50% full. Adding 4 cups of water increased the percentage by 20% of the total capacity of the bowl.

You can use the percent change formula to solve the total capacity of the bowl:

Percent Change $=\frac{ChangeinValue}{OriginalValue}$

$\frac{20}{100}=\frac{4}{x}$

$\frac{1}{5}=\frac{4}{x}$

$x=20$

The total capacity of the bowl is 20 cups, but the question asks for the total number of cups currently in the bowl. You know the bowl is 70% full. You can ask the question, "What is 70% of 20?" and solve:

$x=\frac{70}{100}\times 20$

$x=\frac{7}{10}\times 20$

$10x=140$

$x=14$

There are 14 cups of water in the bowl.