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, April 28, 2008

Ai Tong School P5 SA1 2006 Math (Q47)

Some villagers were building a bridge across a river. On the first week, they built 210 m of the bridge. On the second week, they built 1/5 of the remaining length. How long was the bridge if the total length that they had built on the first two weeks was twice the remaining length to be built?

Solution



7 units ----- 210
1 unit ----- 210 divided by 7 = 30

Length of bridge ----- 210m + 5 units
= 210m + (5 x 30m)
= 210m + 150m
= 360m

Answer: The length of the bridge is 360m.

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