Question 599149
Nacy can mow the lawn in 5 hours. If Craig helps, they can complete the job in 2 2/9 hour.
 How Long would it take Craig to do the job alone ??
:
Let c = Craig's time alone
:
Let the completed job = 1
:
Change 2 2/9 to {{{20/9}}} hrs
:
{{{(20/9)/5}}} + {{{(20/9)/c}}} = 1
multiply by 5c
{{{(20/9)c}}} + {{{(20/9)(5)}}} = 5c
:
Multiply by 9
20c + 20(5) = 9(5c)
100 = 45c - 20c
100 = 25c
c = {{{100/45}}}
c = 4 hrs, Craig's time alone