Question

There are currently 499 students enrolled in Webster Elementary School, and the number of students is increasing at the rate of 15 students per year. Currently the annual expense to educate one student is $1,252, and the expense to educate one student is decreasing at the rate of $43 per year. Use the product rule to determine the rate at which the total expense to educate the students at Webster Elementary School is currently changing per year.

Answer 1

Answer: Cost is decreasing at $2,677 per year.

Step-by-step explanation:

The number of students in the school is increasing by 15 students a year.

The cost of that is:

= 15 * 1,252

= $‭18,780‬

The cost is also decreasing at a rate of $43 per student per year. There are currently 499 students. The total decrease is therefore:

= 43 * 499

= $‭21,457‬

The change is:

= Increase in cost - Decrease in cost

= 18,780 - 21,457

= - $2,677

Cost is decreasing at $2,677 per year.