To determine the correct old and new prices based on a 25% increase, we can use the following formula:
New Price = Old Price × (1 + Percentage Increase)
Given that the percentage increase is 25%, we can express it as a decimal: 1 + 0.25 = 1.25
So, the New Price can also be calculated from the Old Price using the formula: New Price = Old Price × 1.25
Now, let's check the provided pairs:
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Old price: $320; New price: $400
- New Price = 320 × 1.25 = $400 (This pair is correct.)
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Old price: $44; New price: $33
- New Price = 44 × 1.25 = $55 (This pair is incorrect.)
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Old price: $28; New price: $35
- New Price = 28 × 1.25 = $35 (This pair is correct.)
-
Old price: $200; New price: $270
- New Price = 200 × 1.25 = $250 (This pair is incorrect.)
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Old price: $15; New price: $18
- New Price = 15 × 1.25 = $18.75 (This pair is incorrect.)
The correct pairs that represent the old and new prices with the 25% increase are:
- Old price: $320; New price: $400
- Old price: $28; New price: $35