30% = 0.3.
0.3*80 = 24, so we know that 30% of 80 is 24.
80 - 24 = 56, so after the sale, the price for a pair of jeans is $56.
10% = 0.1
0.1*56 = 5.6, so with the coupon, we get $5.60 off.
56 - 5.60 = 50.40
The jeans cost $50.40 after the sale and the coupon.
