Question

Barry is shopping for a new sweater that originally cost $50.00. The department store has all items marked down by 20%. He also has a coupon for an additional 10% off all purchases.

Barry
Since all items are marked down by 20%, and I have an additional 10% off, that means
I get a 30% discount.

The cost of the sweater is $50.00 – $15.00 = $35.00.
Describe Barry’s mistake. Then calculate how much Barry will pay for the sweater.

Answer 1

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Answer:

• mistake: the base for the additional discount is not the original price
• $36

Explanation:

The marked-down price is ...

$50 × (1 - 20%) = $50 × 0.80 = $40

Barry gets a 10% discount on that price, so his discount is ...

$40 × 0.10 = $4

Barry pays $40 -4 = $36.

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Barry would be correct if the "additional 10% off" were based on the original price, but it isn't. It applies to the already-discounted price.