Answer:
$21
Explanation:
This is just a preportion. If you work 20/100 = 7/x you need to multiply 7 times 100 leaving you with 700. Then, you divide that by 20 and get 35. So, $7 is 20% of 35. Now, you have the information needed to set up your next preportion. All you have to do is 60/100 = x/35. Again, multiply 35 times 60, which is 2,100. You divide that by 100 and have $21 as your final answer.
A 60% discount would be $21.