51=60x
—- ——
60 60
0.85=x
Therefore to find the percent discount subtract 1 (which is 100%)-0.85
This gives you 0.15, or a 15% discount.
You can check by multiplying 60 by 0.15, which gives you 9, then subtracting 60-9, which gives you 51.
15% discount.
Hope this helps!!
