This one was fun.
The big thing that you have to remember about working with percents is what they actually are in decimal form. For example the problem's 240% in decimal form is 2.40. Keeping that in mind we can work this problem sort of easily...
68000 = 2.40
what we want to know is what number is equal to 1.00 (aka 100%) So, we divide both sides by 2.40
68000/2.4 = 2.4/2.4
28333.3 = 1.00 or 100%
I think that works.
HAVE A WONDERFUL TIME