Answer:
28 kwh
Step-by-step 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
