Pierre started driving from City D towards City E at 15 30 at an average speed of 60 km/h. Seth began driving from City D towards City E at 17 20 at an average speed of 110 km/h.
- At what time did Seth pass Pierre on the road?
- 1110 hours after passing Pierre, Seth reached City E. At what time did Pierre reach City E?
(a)
From 15 30 to 17 20 = 1 h 50 min
Time that Pierre travelled before Seth started driving = 1 h 50 min
1 h = 60 min
1 h 50 min = 1
5060 h = 1
56 h
Distance that Pierre travelled before Seth started driving
= 1
56 x 60
=
116 x 60
= 110 km
Difference between Seth's and Pierre's speed
= 110 - 60
= 50 km/h
Time that Seth took to catch up with Pierre
= 110 ÷ 50
= 2.2 h
= 2 h 12 min
2 h 12 min after 17 20 = 19 32
Time that Seth passed Pierre on the road = 19 32
(b)
1
110 h = 1 h 6 min
Total time that Seth travelled
= 1 h 6 min + 2 h 12 min
= 3 h 18 min
3 h 18 min = 3
1860h = 3
310h
Distance between City D and City E
= 3
310 x 110
= 363 km
Time that Pierre travelled from City D to City E
= 363 ÷ 60
= 6.05 h
= 6 h 3 min
6 h 3 min after 15 30 = 21 33
Time that Pierre reached City E = 21 33
Answer: (a) 19 32; (b) 21 33