Question

Margaret opened a new case of light bulbs. The case contained 3 boxes of light bulbs with 8 light bulbs in each box. Margaret threw 2 of these light bulbs in the trash because they were damaged. Then she took 7 of the light bulbs out of the case. Which expression can be used to show that there are 15 light bulbs still in the case?

a. 3 * 8 - 2 - 7

b. 3 * (8 - 2 - 7)

c. 3 * (8 - 2) - 7

d. 3 * 8 - 2 + 7

Answer 1

To find the remaining number of light bulbs in the case after some were discarded and some were taken out, we subtract the damaged and removed light bulbs from the total. The correct expression to show that there are 15 light bulbs left is '3 * 8 - 2 - 7'.

Step-by-step explanation:

The expression to show that there are 15 light bulbs still in the case after Margaret's actions can be calculated as follows:

1. There are 3 boxes of light bulbs with 8 light bulbs in each box, so the total number of light bulbs is 3 multiplied by 8.
2. She threw away 2 damaged light bulbs.
3. She then took 7 light bulbs out of the case.
4. To find the remaining light bulbs, we subtract the 2 damaged light bulbs and the 7 light bulbs she took out from the initial total.

Therefore, the expression to calculate the remaining light bulbs is:

3 * 8 - 2 - 7

This simplifies to 24 - 2 - 7, which equals 15. So, the correct answer is a. 3 * 8 - 2 - 7.