Question

By decreasing each dimension by 1 unit, the area of a rectangle deceased from 40 square feet to 28 square feet. Find the percent decrease in area.

Answer 1

30%

Explanation:

Initial area is 40 square feet

Final area is 28 square feet

Difference between the initial and final areas will be 40-28=12 square feet

Taking the initial area as the base area and expressing the area change in percentage then the percentage decrease will be equivalent to

`\frac {12* 100}{40}=30`

Therefore, the decrease in area expressed as a percentage is equal to 30%