Question

A water tank holds 500 liters of water. After some water is used, it holds 400 liters. What is the percent decrease in water?
A
25%
B
20%
C
10%
D
15%

Answer 1

To find the percent decrease in water, we can use the formula for percent change:

\[
\text{Percent Decrease} = \left(\frac{\text{Initial Amount} - \text{Final Amount}}{\text{Initial Amount}}\right) \times 100
\]

In this case, the initial amount of water in the tank is 500 liters, and the final amount is 400 liters.

1. Calculate the decrease in the amount of water:
\[
\text{Decrease} = \text{Initial Amount} - \text{Final Amount} = 500 - 400 = 100 \text{ liters}
\]

2. Now, calculate the percent decrease:
\[
\text{Percent Decrease} = \left(\frac{100}{500}\right) \times 100 = 0.2 \times 100 = 20\%
\]

Thus, the percent decrease in water is **20%**.

The answer is **B**.