Ai Tong Sch 2009 P6 CA1 Math Paper 2 Q12

20 similar pails of water can fill 5/12 of a container. Another 8 similar pails and 105 similar bowls of water are needed to fill the container to its brim. How many such bowls of water are needed to fill the empty container completely?

Solution

20 pails --> 5/12 of container (x2)

8 pails + 105 bowls --> remaining 7/12 of container (x5)

40 pails --> 10/12 of container (after x2)

40 pails + 525 bowls --> 35/12 containers (after (x5)

From the above we can see that 525 bowls can fill up:-

525 bowls --> 35/12 - 10/12 = 25/12 containers

25/12 --> 525 bowls

1/12 --> 525 divided 25 = 21 bowls

(Full container) 12/12 --> 12 x 21 = 252

Answer: 252 bowls

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