lisa can shovel snow from her driveway in 40 minutes jim can do the same job in 50 minutes how long would it take lisa and jim to shovel the driveway together?

lisa's rate = 1/40

jim's rate = 1/50
combined rate = 1/40 + 1/50 = 9/200

time for job = 1/(9/200) = 200/9 or 22 2/9 or appr. 22.22 minutes

To find out how long it would take Lisa and Jim to shovel the driveway together, we need to determine their combined rate of shoveling.

First, let's find their individual rates. Lisa can shovel the driveway in 40 minutes, which means in one minute, she can shovel 1/40th of the driveway. Similarly, Jim can shovel the driveway in 50 minutes, so his rate is 1/50th of the driveway per minute.

To find their combined rate, we add their individual rates together:

1/40 + 1/50 = (50/2000) + (40/2000) = 90/2000 = 9/200

Therefore, when working together, they can shovel 9/200th of the driveway in one minute.

To determine how long it would take them to finish the job together, we need to invert this combined rate:

1 / (9/200) = 200/9

This means that it would take Lisa and Jim approximately 22.22 minutes to shovel the driveway together.