Question 1179355
It takes Tom 1/(1/2) or 2 hours to do it alone.
It takes Jerry 1/(2/3) or 3/2 hours to do it alone. 

Tom does (x/2) of the lawn per hour and Jerry does 2x/3 of the lawn per hour
together (x/2)+(2x/3)=1 
and multiplying by 6, 3x+4x=6
7x=6
x=6/7 of an hour together.

Tom will do 3/7 of it and Jerry will do 4/7 of it.