Question

Five days a week, you carpool with 3 co-workers and take turns driving each week. It is 14 miles from your home to your office. When you drive the carpool you must go an extra 4 miles to pick up your co-workers. If your car averages 18 miles per gallon, about how many gallons of gas should you save every 4 weeks by carpooling?

Answer 1

she saves 8.8888888 gallons of gas every week by carpooling.

Answer 2

I will save 21.11 gallons in 4 weeks of car pooling.

Explanation:

If i have to go office alone then in 4 weeks i will be driving my car = 2×distance from office to home×number of days = 2×14×(4×5) = 28×20 = 560 km.

Now when i carpool with 3 co-workers then i have to drive my car only for 1 week out of 4 weeks.

Means i will be driving total distance = 2× ( distance form office to home + addition distance to pickup co-workers) × number of days

= 2 × (14+4) × 5= 180 km

Now the distance I drove less in 4 weeks = 560 - 180 = 380 km

My car averages 18 miles per gallon gas.

Therefore amount of gas I saved in 4 weeks = 380/18 = 21.11 gallons