Answer:
Explanation:
Remark
The problem with this question is that you don't exactly know what the 25% does.
I think the way to do the problem is to consider where the 42 dollars comes from.
I think the beginning part of the problem is to develop an equation which you may not be able to solve.
So the cost using the 30% reduction is 0.7c where c is the original cost. But the 25% makes the actual cost for the person = 0.7c - 25% of 0.7c
The result is 42 dollars.
0.7c - 0.25*0.7c = 42
If I'm right, that can be solved.
0.7c - 0.175c = 42
0.525c = 42
c = 42/0.525
c = 80 dollars.
So before all the reductions and everything else, the case actually cost 80 dollars.