Question

A track star ran the 100-meter event in six track meets. Her average time for all six meets was 11.8 seconds. She could not find the record for her running time in the last meet, but she had all the other ones: 11.1 seconds, 11.2 seconds, 12 seconds, 12.1 seconds, 11.7 seconds. What was her running time for her last meet?

a) 12.2 seconds
b) 11.9 seconds
c) 11.5 seconds
d) 11.3 seconds

Answer 1

(11.1 + 11.2 + 12 + 12.1 + 11.7 + s)/6 = 11.8

(58.1 + s)/6 = 11.8

58.1 + s = 70.8

s = 12.7 seconds

None of the choices shown are correct.

Answer 2

To find the running time of the last meet, total time for all meets calculated as the average time multiplied by the number of meets (70.8 secs), then subtract the cumulative time of the other five meets (58.1 secs). The running time for the last meet is 12.7 seconds, which does not match any of the provided options.

Step-by-step explanation:

The student's question asks to determine the track star's running time for the last meet given her average time and the times of five other meets. To solve this, we first calculate the total time for all six meets by multiplying the average time by six. Then we subtract the sum of the times from the five provided meets. The difference is the running time for the last meet.

Here's the step-by-step calculation:

1. Calculate total time for all six meets: 6 meets × 11.8 seconds/meet = 70.8 seconds.
2. Sum the times of the five meets: 11.1 + 11.2 + 12 + 12.1 + 11.7 = 58.1 seconds.
3. Subtract the sum from step 2 from the total time: 70.8 seconds - 58.1 seconds = 12.7 seconds.
4. Thus, the running time for the last meet is 12.7 seconds.

Comparing with the multiple-choice options, there seems to be a discrepancy as none of the answers match 12.7 seconds. It's likely there's a misunderstanding or miscommunication in the options provided with the real answer.