It takes 1.5hours for Tim to mom the lawn. Linda can mow the same lawn in 2hours. Approximately how will it take John and Linda, work together, to mow the lawn?

Question

anonymous · Answer

This is a problem relating to harmonic average.
Based on frequency (1/time):
Tim: 1/1.5 = 2/3 lawn per hour
Linda: 1/2 = 1/2 lawn per hour

Tim + Linda: 1/2 + 2/3 = 7/6 lawn per hour
Time (1/frequency):
6/7 hour per lawn, therefore working together they take 6/7 hour to mow the lawn

anonymous · Answer

If you have seen the sum of parallel resistors, the formula works for the same reason. 
1/Rt = 1/R1 + 1/R2

anonymous · Answer

what is the final answer?

anonymous · Answer

6/7 hour

anonymous · Answer

tell me in minutes if possible please

anonymous · Answer

thank you adfriedm

radar · Answer

Depends on how long John takes to mow the lawn.  That information was not provided.  Only provided what Tim could do the lawn.  No solution, or problem is worded wrong.

radar · Answer

Jovis209 did you copy this problem correctly?

anonymous · Answer

yeap i did