Question

Mai and Elena are shopping for back-to-school clothes. They found a skirt that originally cost $30 on a 15% off sale rack. Today, the store is offering an additional 15% off.

To find the new price of the skirt, in dollars, Mai says they need to calculate 30. 0.85 0.85. Elena says they can just multiply 30.0.70.
1. How much will the skirt cost using Mai's method?
2. How much will the skirt cost using Elena's method?
3. Explain why the expressions used by Mai and Elena give different prices for the skirt.

Answer 1

Mai

Explanation:

1. 21.675 R $22

2. $21

Mai is the correct method because 15%-100%=85, which shows the percentage that is left to multiple. Then she multiples 0.85 times 2 as she was able to take off 15% twice. Elena's is incorrect because she added the two 15% off and subtracted that by 100 giving her 70. Which is the incorrect decimal to multiple by. Hope this helps.

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