Answer:
Discount percentage is 16.4% for the customers who purchase 6- coupon book .
Step-by-step explanation:
Formula
As given
Your station charges $15.95 for an oil change.
Original charge of the oil change for 6 times = 6 × Original charge for oil change .
= 6 × 15.95
= $ 95.7
As a promotion you sell six coupons for oil changes for $80.
Discount = Original charge of the oil change for 6 times - Charge by six coupons for oil changes .
= $95.7 - $80
= $ 15.7
Putting all the values in the above
Discount percentage = 16.4%
Therefore the discount percentage is 16.4% for the customers who purchase 6- coupon book .