math
posted by Al .
Shop A sold a notebook for $1200. This was 125% of the price of a similar notebook sold in Shop B. Find the price of the notebook in Shop B.
During a sale, both shops gave the same percentage of discount. Dennis bought the notebook from Shop B and found that she paid $175.20 less than the discounted price in Shop A.
What is the percentage discount given during the sale?

1. 1.25P = 1200.
P = 1200 / 1.25 = $960
2. 960960r = 12001200r  175.20.
960960r = 1200r + 1024.80.
960r + 1200r = 1024.80  960.
240r = 64.8.
r = 64.8 / 240 = o.27 = 27%.