Asher runs 100 metres for 5 times. The average time taken for his first three runs is 16.2 seconds. He aims to have an average timing of 13.8 seconds for his five runs.
- What is the average time he needs to take for his 4th and 5th run in order to achieve his aim?
- If he runs 3 seconds faster in one of the five runs, what would be his average time for the five runs?
(a)
Total timing for first three runs
= 3 x 16.2
= 48.6 s
Total timing needed if the average is to be 13.8 s
= 13.8 x 5
= 69 s
Total timing for last two runs to achieve his aim
= 69 - 48.6
= 20.4 s
Average timing for last two runs
= 20.4 ÷ 2
= 10.2 s
(b)
New average
= (69 - 3) ÷ 5
= 13.2 s
Answer(s): (a) 10.2 s; (b) 13.2 s