Question

ABC company wants to construct a hall for its monthly townhall.The estimation comprises $m$ hours of labor, where $m>80$. The company's goal is for the estimate to be within $8$ hours of the actual number of hours of labor.If the company meets the goal and it takes $a$ hours of actual labor, which inequality represents the relationship between the estimated number of hours of labor and the actual number of hours of labor ?

• A. $a+m\le 8$
• B. $a\ge m+8$
• C. $a\le m-8$
• D. $-8\le a-m\le 8$

Answer 1

The correct option is D $-8\le a-m\le 8$

The number of hours of actual labor is $a$

The estimated number of hours of labor is $m$

The difference between them must be less than or equal to $8$

$\Rightarrow |a-m|\le 8$

$\Rightarrow -8\le a-m\le 8$