Students in a class are solving questions based on percentage discounts. One question requires the students to calculate the cost of two bikes, with a 8% discount on each bike. One of the groups calculates the total cost of the bikes and then deducts 16% from the total cost. The method used by this group is :

Question

Accepted Answer

Option 3 is the correct answer because the group made an error in their calculation by deducting a 16% discount from the total cost of the two bikes instead of applying an 8% discount to each bike individually. When calculating percentage discounts, it is crucial to apply the discount to each item separately, especially when the discount percentage is specified for each item. By deducting 16% from the total, the group incorrectly assumed that the discounts on the two bikes could be combined into a single percentage applied to the total cost, which is not mathematically accurate.

Here's why each of the other options is incorrect:

1. **Option 1: Correct and is the only way to calculate the discount and cost.**
   - This option is incorrect because the method used by the group is not correct. Applying a 16% discount to the total cost does not accurately reflect the 8% discount that should be applied to each bike individually. Therefore, it is not the correct method, nor is it the only way to calculate the discount and cost.

2. **Option 2: An alternate strategy to solve the question.**
   - This option is incorrect because the method used by the group is not a valid alternate strategy. An alternate strategy would still need to adhere to the correct application of the discount, which is 8% on each bike. The group's method of applying a 16% discount to the total cost does not achieve the correct result and is not a legitimate alternate strategy.

4. **Option 4: False, since they have deducted 16% from the total instead of 16% from the average of the total.**
   - This option is incorrect because the issue is not about applying a 16% discount to the average of the total. The problem lies in the fact that the group applied a 16% discount to the total cost, which is incorrect. The correct approach is to apply an 8% discount to each bike individually, not to focus on the average or any other percentage.

In summary, Option 3 is correct because it identifies the specific error made by the group: applying a 16% discount to the total cost instead of the correct 8% discount to each bike.