Question

A type of electric car can travel 5 on 1 kilowatt hour of electricity. How many kilowatt hours of electricity would it take Helen to drive her electric car to her aunts house and​ back? Helen lives 70 miles from her aunt.

Answer 1

28 kwh

Explanation:

given that the care can travel 5 miles on 1 kwh, i.e

5 miles travelled -----> uses 1 kwh

hence to find the unit rate:

1 mile travelled ----> Uses 1 kwh ÷ 5 = 1/5 kwh

We are also given that Helen lives 70 miles away from her aunt.

Hence a return trip (i.e "to aunts house and back"), will be 70 x 2 = 140 miles

using the unit rate that we found above, we can find the number of kwh that is used to travel 140 miles

140 miles = 140 miles x unit rate

= 140 x 1/5

= 28 kwh