Final answer:
Jeremy cannot add the percentages to find the final cost because the discounts are sequential, not simultaneous. The correct way is to apply each discount in turn: first 15% off and then an additional 10% off the reduced price, resulting in a final cost of $45.90, not $45 as would be implied by simply taking 25% off.
Step-by-step explanation:
Jeremy cannot find the cost of the sneakers simply by adding the percentages because the discounts are taken sequentially, not simultaneously. First, his sneakers are on sale for 15% off. To calculate this, we convert 15% to a decimal and multiply it by the cost of the sneakers.
$60 × 0.15 = $9
After the first discount, the sneakers cost $60 - $9 = $51. Next, Jeremy uses a coupon for an additional 10% off. Again, converting the percent to a decimal and multiplying it by the new price:
$51 × 0.10 = $5.10
Subtract this amount from $51 to find the final cost:
$51 - $5.10 = $45.90
If Jeremy had instead calculated 25% off the original price:
$60 × 0.25 = $15
The cost would be:
$60 - $15 = $45
The result of $45 is not equal to the correct final cost of $45.90, demonstrating that you cannot merely add the percentages to find the final cost when discounts are applied sequentially.