HSPT Math · Question of the Day

HSPT Math Question of the Day

A fresh daily question to build accuracy, reinforce recall, and turn practice into a steady habit.

Thursday, September 17, 2026

The length of a rectangular field is increased by 20%, and its width is decreased by 10%. What is the resulting percentage change in the area of the field?

Keep practicing HSPT Math

Question of the Day

Answer today's HSPT Math question, reveal the full explanation, then keep the streak going with a new question every day.

The length of a rectangular field is increased by 20%, and its width is decreased by 10%. What is the resulting percentage change in the area of the field?

10% increase
10% decrease
8% increase (correct answer)
8% decrease

Explanation: Let the original length be $L$ and the original width be $W$ . The original area is $A = LW$ . The new length $L'$ is $L + 0.20L = 1.2L$ . The new width $W'$ is $W - 0.10W = 0.9W$ . The new area $A'$ is $L'W' = (1.2L)(0.9W) = 1.08LW$ . To find the percentage change, use the formula $\frac{\text{New Area} - \text{Old Area}}{\text{Old Area}} \times 100\%. This is \(\frac{1.08LW - LW}{LW} \times 100\% = \frac{0.08LW}{LW} \times 100\% = 0.08 \times 100\% = 8\%$ . Since the factor 1.08 is greater than 1, it is an 8% increase.