At 9.30 am, Mr Yeo left Town A for Town B driving at a speed of 75 km/h throughout his journey. At 10.30 am, Mr Lee also left Town A for Town B driving at a certain speed. He kept to the same speed throughout his journey. At 1.30 pm, both of them passed a Shopping Mall that was 150 km way from Town B. How many minutes earlier did Mr Lee reach Town B than Mr Yeo?
Solution
(Town A to Shopping Mall)
Yeo --> distance = 75 km/h x 4h = 300 km
Lee ---> speed = 300 km divided by 3h = 100 kmh
(Shopping Mall to Town B)
Lee --> time = 150 km divided by 100 km/h = 1.5 h
Yeo --> time = 150 km divided by 75 km/h = 2 h
2 h - 1.5 h
= 0.5 h
= 30 minAnswer: 30 minutes
1 comment:
There is a mistake in the diagram. It should be Lee, not Lim.
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