Set 2: Linear Functions (Advanced)

**Choice C is the best answer.** 500 - 20t = 0. t = 25

Explanation

Answer: C

PROBLEM

A water tank drains at rate D(t) = 500 - 20t liters. When is it empty?

A.

30

B.

20

C.

25

✓ Correct

D.

480

Detailed Explanation

Choice C is the best answer. 500 - 20t = 0. t = 25

Why others are wrong:

A: 30 is incorrect because it does not satisfy the equation.

B: 20 is incorrect because it does not satisfy the equation.

D: 480 is incorrect because it does not satisfy the equation.