The cleanup crew is picking up litter from the side of the road. if one crew member can clean up a mile of road in 45 minutes, and another crew member can clean up a mile of the road in 70 minutes, approximately how much time will it take the crew members to clean up a mile of the road if they work together?
Note that the first guy cleans 1/45 of the road in one minute
And the second guy cleans 1/70 of the road in one minute
Add these fractions
1/45 + 1/70 =
[70 + 45 ] 115
________ = _____
45 * 70 3150
Take the reciprocal of this fraction =
3150
____ ≈ 27.39 min for both working together
115