Question 155235
If you can cut the lawn in 2 hours, and your spouse can do it in 3 hours, how
 long would it take if you work together? What assumptions (if any) did you
 make to arrive at your solution?
:
Let t = time required working together
:
Let the completed job = 1
:
The fraction of the job, that each does, adds up to 1
;
{{{t/2}}} + {{{t/3}}} = 1
Get rid of the denominators multiply each term by 6, results:
3t + 2t = 6
:
5t = 6
t = {{{6/5}}}
t = 1.2 hrs working together
:
:
Check solution on calc: enter (1.2/2) + (1.2/3) = 1
:
You have to assume that you have two lawn mowers!!