Question 767056
Original money quantity, N.

{{{N-(3/8)N-(1/4)N=960}}} fits the description of spending portions from N and having 960 as a result after that spending occurred.  


From that equation, you can factor N on the left side, and you have a couple of choices how to go next.


{{{N(1-3/8-1/4)=960}}}
Maybe just do the arithmetic computation in denominations of (1/8) units.
{{{1-3/8-1/4=8/8-3/8-2/8}}}
{{{(8-3-2)/8=(8-5)/8=3/8}}}


That allows revising equation to:
{{{N(3/8)=960}}}
{{{N=960(8/3)}}}
{{{N=(960/3)*8=320*8}}}
{{{highlight(N=2560)}}}