Question

answer the questions below.
note that a change can be an increase or a decrease.
for an increase, use a positive number.
for a decrease, use a negative number.
(a) debra pumped 12 gallons of water out of her pool. this was done over a period of 2 minutes at a constant rate. what was the change in the amount of water in the pool each minute?
(square) gallons
(b) kareem added 3 fish to his pond each day for 15 days. what was the total change in the number of fish in the pond?
(square) fish

Explanation:

Step 1: Solve part (a)

Debra pumped out 12 gallons in 2 minutes. Pumping out means a decrease, so we use a negative number. The rate (change per minute) is total change divided by time. So, the change in water per minute is $\frac{-12}{2} = -6$ gallons per minute.

Step 2: Solve part (b)

Kareem added 3 fish each day for 15 days. Adding means an increase, so we use a positive number. The total change is the rate per day times the number of days. So, the total change is $3\times15 = 45$ fish.

Answer:

(a) The change in the amount of water in the pool each minute is -6 gallons.
(b) The total change in the number of fish in the pond is 45 fish.