Question

NEED HELP A mine extracts 2 tons of ore in an hour. Of the total ore extracted in a day, 4 tons is purchased by the government and more than 10 tons is sold to a mineral extractor. If the mine operates for x hours in a day, what is the simplest inequality that represents the number of hours the mine must operate to meet its obligations?

A.
x > 3
B.
x > 4
C.
x > 5
D.
x > 7

Answer 1

D. x > 7

Explanation:

The mine operates x hours per day and extracts 2 tons of ore per hour.

The amount of ore extracted as a function of hours of operation is

2x

The mine must produce 4 tons plus more than 10 tons each day. The mine must produce more than 14 tons in one day. That means that 2x must be greater than 14.

2x > 14

Divide both sides by 2.

x > 7

Answer: D. x > 7