word problem

Question

Maria can shovel snow from her driveway in 65 minutes. Bill can do the same job in 40 minutes. How long would it take Maria and Bill to shovel the driveway if they worked together?

Answer 1

In one minute, Maria does 1/65 of the driveway.

In one minute, Bill does 1/40 of the driveway.

 

Working together they take "x" minutes.

 

In x minutes, Maria does x/65 of the driveway.

In x minutes, Bill does x/40 of the driveway.

 

x/65 + x/40 = 1                 1 because it is one job.  520 is the common denominator.

8x/520 + 13x/520 = 1

8x + 13x = 520

21x = 520

x = 24.76                           Usually these work problems come out with integers. Please check the numbers in the problem.