Answer: 98%
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Step-by-step explanation:
The customer saves 15%, but still pays the remaining 85%. The two percentages add to 100%.
85% of $900 = 0.85*900 = 765
After the 15% discount is applied, the customer would pay $765
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Then after the sale, the price is marked up by 15%
This means we'll multiply by 1.15 to indicate a 15% increase
1.15*765 = 879.75
Notice that we don't get back to the original price (900) even though we increased by the same percentage as before. This is because 15% of a smaller number is a smaller amount; ie we have a smaller increase compared to the decrease earlier.
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Afterwards, divide the value 879.75 over the original price of $900
879.75/900 = 0.9775
Move the decimal point two spots to the right to end up with 97.75%
That percentage rounds to 98% when rounding to the nearest whole percent.