Final answer:
The student's question involves tracking a series of additions and subtractions starting with 20 kids and applying the given changes. After working through the sequence of events, the final count is 18 kids remaining, which does not match any of the given options. There could potentially be a typo in the question. If the typo is in step 7 and it's meant that 1/4 remained rather than left, then the final answer would be 16 kids.
Step-by-step explanation:
To solve this math problem, we'll start with 20 kids and track the changes as given in the sequence: 1/2 left, 5 came back, 2 went away, 12 went away, 3 came back, 1/4 left, then 15 came back. Let's work through the steps:
- 20 kids initially.
- 1/2 left, so that's 20 * 1/2 = 10 kids left, meaning 10 kids remain.
- 5 came back, increasing the number to 10 + 5 = 15 kids.
- 2 went away, leaving 15 - 2 = 13 kids.
- 12 went away, leaving 13 - 12 = 1 kid.
- 3 came back, making it 1 + 3 = 4 kids.
- 1/4 left, so 1/4 of 4 is 1 kid leaving, thus 4 - 1 = 3 kids remain.
- Finally, 15 came back, resulting in 3 + 15 = 18 kids.
Therefore, the answer is 18 kids are left, which is not in the options provided. If this is a typo in the question and you meant 1/4 of the kids remained rather than left, the answer would be different. In that case, the final step would result in only 1 kid remaining after the 1/4 left, and then with 15 coming back, we would have a total of 16 kids.