The table shows the time taken by Simon to run 100 metres during his training sessions. After 3 attempts, Simon wanted to improve his average time taken by 1.2 seconds by running faster in the 4
th attempt. How fast should he run in the 4
th attempt in order for him to make the improvement?
Attempt |
1st |
2nd |
3rd |
4th |
Time taken (in seconds) |
17 |
20 |
23 |
? |
Total time that Simon took for the first 3 attempts
= 17 + 20 + 23
= 60 s
Average time that Simon took for the first 3 attempts
= 60 ÷ 3
= 20 s
New average time that Simon took for the 4 attempts
= 20 - 1.2
= 18.8 s
Total time that Simon took for the 4 attempts
= 4 x 18.8
= 75.2 s
Time that Simon should run in the 4
th attempt in order for him to make the improvement
= 75.2 - 60
= 15.2 s
Answer(s): 15.2 s