At 11.55 a.m., David started driving from Town P to Town Q which was 490 km away. For the first 250 km, he travelled at an average speed of 75 km/h. He then decreased his speed by 30 km/h and completed the remaining journey.
- Find the total time taken for the whole journey. Express your answer as a mixed number.
- At what time did she reach Town Q?
(a)
Time taken for the first 250 km
= 250 ÷ 75
= 3
2575 = 3
13 h
Speed for the remaining journey
= 75 - 30
= 45 km/h
Remaining distance
= 490 - 250
= 240 km
Time taken for the remaining journey
= 240 ÷ 45
= 5
1545= 5
13 h
Total time taken
= 3
13 + 5
13= 3
13 + 5
13= 8
23 h
(b)
1 h = 60 min
23 h =
23 x 60 = 40 min
8 h 40 min after 11.55 a.m. = 8.35 p.m.
Answer(s): (a) 88
23 h; (b) 8.35 p.m.