Correct Answer:
C. 410
This problem involves a direct proportional relationship between time and the number of jumps. We are given that the girl jumps 820 times in 1 hour. To solve for the number of jumps in 30 minutes, we first recognize the relationship between the two time periods.
- One hour is equivalent to 60 minutes. Therefore, 30 minutes represents exactly half of an hour.
- To find the number of jumps in 30 minutes, we simply divide the total number of jumps in one hour by two: 820 jumps / 2 = 410 jumps.
- Distractors (A) 205, (B) 350, and (D) 600 are incorrect as they do not reflect this direct halving of the activity over half the time period.