Question

which situation has a constant rate of change? select all that apply.
a on a treadmill, jamie runs at a speed of 7 miles per hour and then walks at a speed of 3 miles per hour.
b disha is paid $8 for every hour she babysits.
c the temperature in an oven decreases 25 degrees every minute after being turned off.
d ellis makes bracelets to sell at a craft fair. she makes 1 per day for a week. then she gets more supplies. she makes 2 bracelets per day the next week.
e a store sells strawberries for $3 per pound.
what is the rate in each situation?

Explanation:

To determine which situations have a constant rate of change, we analyze each option:

Option A

Jamie runs at 7 miles per hour (constant speed) and then walks at 3 miles per hour (another constant speed). However, the problem is about the rate of change in the situation. Wait, actually, both running and walking speeds are constant rates (even though there’s a switch, each segment has a constant rate). But let’s re - evaluate: The speed during running (7 mph) and walking (3 mph) are constant rates of change of distance with respect to time. So this has constant rates (7 mph and 3 mph).

Option B

Disha is paid $8 for every hour she babysits. The rate of pay (dollars per hour) is constant: $8 per hour. So this has a constant rate of change (8 dollars per hour).

Option C

The temperature in an oven decreases 25 degrees every minute after being turned off. The rate of temperature change is constant: - 25 degrees per minute (negative because it’s decreasing). So this has a constant rate of change (-25 degrees per minute).

Option D

Ellis makes 1 bracelet per day for a week, then 2 per day the next week. The number of bracelets made per day changes (from 1 to 2), so the rate of change (bracelets per day) is not constant.

Option E

A store sells strawberries for $3 per pound. The price per pound is constant: $3 per pound. So this has a constant rate of change (3 dollars per pound).

Answer:

A. On a treadmill, Jamie runs at a speed of 7 miles per hour and then walks at a speed of 3 miles per hour. (Rates: 7 miles per hour, 3 miles per hour)
B. Disha is paid $8 for every hour she babysits. (Rate: 8 dollars per hour)
C. The temperature in an oven decreases 25 degrees every minute after being turned off. (Rate: - 25 degrees per minute)
E. A store sells strawberries for $3 per pound. (Rate: 3 dollars per pound)