It takes Harland 15 minutes to rake all leaves in the front yard. If Trudy scatters the leaves while Harland rakes, it takes him 20 minutes to rake the leaves. How many minutes does it take Trudy to scatter all the leaves?

5 minutes

12 minutes

45 minutes

60 minutes

Annmarie can plow a field in 240 minutes. Gladys can plow a field 80 minutes faster. If they work together, how many minutes does it take them to plow the field?

96 minutes

160 minutes

400 minutes

480 minutes

Byron can fill a drying rack with dishes in 15 minutes. While Byron fills the drying rack, Emmitt takes dishes out of the drying rack and puts them in bins. With Emmitt taking dishes out of the drying rack, it takes 35 minutes for Byron to fill the drying rack.

Which of the following can be used to determine the amount of time it takes for Emmitt to empty the drying rack if Byron is not adding dishes?

1 over 15 plus 1 over 35 equals 1 over x

1 over 15 minus 1 over x equals 1 over 35

1 over 35 minus 1 over x equals 1 over 15

1 over 15 minus 1 over x equals x over 35