A tour bus which left Kuala Lumpur at 10.30 a.m. was scheduled to reach Singapore by 5 p.m. After travelling for 2 hours at its usual speed, the bus stopped for 30 minutes due to some problems. In order to reach Singapore punctually, the bus increased its speed by 8.5 km/h. Given that the bus took 4 hours to complete the rest of the journey, find the distance between Kuala Lumpur and Singapore.[5 marks][Answer given: 442 km]
10.30 am 2 h ---> S + 8.5 km/h, 4 h 5 pm
|-----------------|-------------------------------|
K 30 min
stop
8.5 x 4 = 34 km Distance covered by the increased speed in 4 h (1 pm to 5 pm)
1/2 h --> 34 km Time lost (due to resting) and the distance it would have had travelled
1 h --> 1 x 2 x 34 = 68 km Original speed 68 km/h
68 x 2 = 136 km
68 + 8.5 = 76.5 km/h
76.5 x 4 = 306 km
136 + 306 = 442 km
It was 442 km.
Subscribe to:
Post Comments (Atom)
Obs,
ReplyDeleteMay I know why 8.5 x 4? & 1/2h --> 34km?
I haved added comments in red. Hope they clear your doubts.
ReplyDelete