how do i solve this problem?

Question

30 minutes before the community pool closed, there were 15 swimmers in the pool . Six minutes later, there were 3 swimmers in the pool. What is the average change per minute in the number of swimmers in the pool?

Answer 1

From the above information, number of minutes taken as x - coordinate and number of swimmers taken as y - coordinate.

Therefore points are (30, 15) and (6, 3).

Here to find the rate of change, use the slope formula.

Let (x₁, y₁) =(30, 15) and (x₂, y₂) = (6, 3)

Slope m = (y₂ - y₁)/(x₂ - x₁)

m = (3 - 15)/(6 - 30)

m = (- 12) / (- 24)

m = 1/2 = 0.5 swimmer/minute.

There are 1/2 number of swimmers per minute in the pool.