This blog is managed by Song Hock Chye, author of Improve Your Thinking Skills in Maths (P1-P3 series), which is published and distributed by EPH.

Monday, August 04, 2008

Maha Bodhi Sch 2007 PSLE Math Prelim Q44

Two motorists, X and Y, travelled on the same route from Town A to Town B. They each drove at a uniform speed but started their journey at a different time of the day.

The table below shows some details of their journey.

If Motorist X reached Town B at 1625, find:
a) the distance between the two towns and
b) the speed at which Motorist Y was travelling.


Consider Motorist X -----
Distance (middle portion) ----- 120 km/h x 2.5 h = 300 km
Total Distance covered ---- 60 km + 300 km + 60 km = 420 km

Answer: The total distance was 420 km.

Motorist Y -----
Middle portion ----- 420 km – 100 km – 100 km = 220 km
Speed ----- 220 km divided by 2.5 hours = 88 km/h

Answer: Speed of Motorist Y was 88 km/h.

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