Question

you have been contracted to pave a rectangular portion of a garden that is 15 feet long and 10 feet wide, with 1 - square - foot pavers. you will have your assistant purchase and deliver the required pavers. the assistant calculated the area of the portion to be paved as 100 square feet. which of the following statements could have been the mistake that the assistant made?

a. the assistant squared the width of the rectangular portion.
b. the assistant calculated the perimeter of the rectangular portion.
c. the assistant added the length and width of the rectangular portion.
d. the assistant multiplied the length and the width of the rectangular portion.
e. the assistant calculated the area of the rectangular portion and doubled it.

Explanation:

First, find the correct area of the rectangle using the formula $A = l\times w$, where $l = 15$ feet and $w = 10$ feet, so $A=15\times10 = 150$ square - feet. The assistant got 100 square - feet. The perimeter of a rectangle is $P=2(l + w)=2(15 + 10)=2\times25 = 50$ (not 100). Squaring the width $w^2=10^2 = 100$.

Answer:

A. The assistant squared the width of the rectangular portion.