Question

A project manager estimates that a project will take $x$ hours to complete, where $x>100$. The goal is for the estimate to be within 10 hours of the time it will actually take to complete the project. If the manager meets the goal and it takes $y$ hours to complete the project, which of the following inequalities represents the relationship between the estimated time and the actual completion time?

• A. $x+y<10$
• B. $y>x+10$
• C. $-10<y-x<10$
• D. $-10\le y-x\le 10$

Answer 1

The correct option is C $-10<y-x<10$

Actual time for completing $=yhours$

Estimated time $=xhours$

Estimated time can be $10hours$ greater or $10hours$ lesser than actual time.

$|x-y|<10$

Or $|y-x|<10$

Hence $-10<y-x<10$