fraction addition

1/3 + 1/7 = Using our fraction calculator, we get: 10/21

When Mike uses a riding mower, it takes him 3 hours to mow his lawn. When he uses a push mower, it takes him 6 hours to mow the lawn. (His sister also can mow the lawn with the push mower in 6 hours.). Mike wanted to get the lawn mowed as quickly as possible, so he paid his sister $10 to mow...