Reggie and Owen took part in a 42 km marathon. Reggie ran half the distance at a speed of 9 km/h and ran slower for the rest of the way at a speed of 9 km/h. Owen ran half his total time at 10 km/h and ran slower for the rest of the time at 10 km/h. If they started the marathon at 3.30 a.m., at what time would each of them finish?
- Reggie
- Owen
(a)
Half of the 42 km marathon = 42 ÷ 2 = 21 km
Time taken by Reggie for the first half of the marathon
= 21 ÷ 9
= 2
13 h
Time taken by Reggie for the last half of the marathon
= 21 ÷ 9
= 2
13 h
Total time taken by Reggie
= 2
13 + 2
13= 4
23 h
1 h = 60 min
23 h =
23 x 60 = 40 min
4
23 h = 4 h 40 min
4 h 40 min after 3.30 a.m. = 8.10 a.m.
Time that Reggie would finish the marathon = 8.10 a.m.
(b)
Time taken by Owen for the first half of the marathon
= 21 ÷ 10
= 2
110 h
Time taken by Owen for the last half of the marathon
= 21 ÷ 10
= 2
110 h
Total time taken by Owen
= 2
110 + 2
110 = 4
210 h
1 h = 60 min
210 h =
210 x 60 = 12 min
4
210 h = 4 h 12 min
4 h 12 min after 3.30 a.m. = 7.42 a.m.
Time that Owen would finish the marathon = 7.42 a.m.
Answer(s): (a) 8.10 a.m.; (b) 7.42 a.m.