Posted by Katie on Thursday, October 27, 2011 at 6:35pm.
Lisa can shovel her drive way in 35 minutes. Tom can shovel the same drive way in 40 minutes. How long will it take them to do the job together?

Help  Steve, Friday, October 28, 2011 at 5:27am
in one minute, Lisa can shovel 1/35 of the driveway
in one minute, Tom can shovel 1/40 of the driveway.
in one minute, they both can shovel 1/35 + 1/40 = 8/280 + 7/280 = 15/280 = 3/56 of the driveway.
So, it will take them 18 2/3 minutes working together.
If b is the time for both,
1/b = 1/35 + 1/40
b = 35*40/(35+40) = 18 2/3
Answer This Question
Related Questions
 Word problems  Jenny can shovel snow from her driveway in 60 minutes. Tom can ...
 MATH HEPL  lisa can shovel the drive way in 35 minutes john the same driveway ...
 algebra  I am unsure of what formula to use for this problem can anyone help me...
 Math  Lisa can shovel snow from her driveway in 45 minutes. Bill can do the ...
 Math  Lisa can shovel her driveway in 30 minutes and Tom can shovel his ...
 algebra 2  lisa can shovel snow from her driveway in 40 minutes jim can do the ...
 Algebra  sue can shovel snow from her driveway in 60 minutes. Tom can do the ...
 algebra  Sue can shovel snow from her driveway in 40 minutes. Tom can do the ...
 ALGEBRA  Janet can shovel snow from her driveway in 55 minutes. Jim can do the ...
 Algebra  WELL SOMEONE HELP ME SOLVER THIS PROBLEM PLEASE!!!!!! Janet can shovel...
More Related Questions