Answer:
75% off
Explanation:
I would personally say use a calculator, but whatever your instructor says.
First, do $600 off. You could also do 75% off first, but you choose. If you subtract $600 from $868, you get $268.
Next, do 75% off. If you take 100% - 75%, you get 25%, or 1/4. Multiply $868 by 1/4 and you get $217, which is the better deal.
So, to conclude, $217 is less than $268, and therefore 75% off is the better deal.