Question 8·Medium·Percentages
A laptop has a listed price of $1,200. During a weekend promotion, the store first discounts the price by 15%, and a shopper then applies a coupon that takes an additional $60 off the discounted price.
What is the final price, in dollars, the shopper pays for the laptop?
For price and discount problems, first decide the order of operations: apply percentage discounts to the original price, then apply any flat dollar coupons to the new price. Convert percentages to decimals (like 15% → 0.15 or 1 − 0.15 = 0.85) and use multiplication for the percent step and subtraction for the coupon step. Writing a single expression, such as original_price*(1 − percent) − coupon, helps you move quickly and avoid forgetting any discount.
Hints
Convert the percent discount into a dollar amount
Start by finding how many dollars 15% of is. Multiply by or by .
Apply the percent discount first
Once you know 15% of , subtract that amount from to get the sale price before using the coupon.
Use the coupon last
After you have the discounted price, subtract $60 from that number to find how much the shopper actually pays.
Desmos Guide
Compute the final price in one expression
In a Desmos expression line, type 1200*0.85 - 60 (using because a 15% discount means you pay of the price), and read the numerical value Desmos gives; that is the final price after both discounts.
Step-by-step Explanation
Find the amount of the 15% discount
A 15% discount means the store takes of the original price off.
Compute 15% of :
So the discount amount is dollars.
Find the price after the 15% discount
Subtract the discount from the original price:
So, after the 15% discount, the laptop costs dollars.
Apply the $60 coupon to the discounted price
Now the shopper uses a coupon that takes an additional $60 off the discounted price of .
Subtract $60 from :
So the final price the shopper pays for the laptop is $960.