Explanation:
Cost = $112 
30% discount coupon on the item he's going to buy
=$112 × 30/100 (or you can write 30%) 
=$168/5 ($33.6)
7% tax on the item=$112 × 7/100(or you can write 7%)
 = $196/25 ($7.84)
Total amount altogether=$112 - $33.6 - $7.84
 =$70.56 
not sure for the answer^^