The table shows the time taken by 4 participants in a race. All the times recorded are in whole numbers. Some of the time recorded were blocked by an ink drop. The average time taken by the 4 participants was 80 seconds. The difference between the time taken by Jeremy and Flynn was 7 seconds. Find the shortest possible time taken by Zeph.
Total time of 4 participants
= 4 x 80
= 320 s

Total time taken by Jeremy, Zeph and Flynn
= 320 - 73
= 247 s

Comparing the time taken by Jeremy and Flynn:
Time taken by the slower runner: 1 u + 7
Time taken by the faster runner: 1 u

Total time taken by Jeremy and Flynn
= 1 u + 7 + 1 u
= 2 u + 7

To find the shortest possible time taken by Zeph, the time taken by him must be as low as possible and a whole number.

Scenario 1
Time taken by Jeremy and Flynn if the time taken by Zeph was 80 s
= 247 - 80
= 167 s

2 u + 7 = 167
2 u = 167 - 7
2 u = 160

1 u = 160 ÷ 2 = 80 (✓) (Possible as all the times recorded are whole numbers.)

Time taken by Zeph = 80 s

Answer(s): 80 s