Archive for September, 2009

Circle & Rectangle

{ September 26, 2009 @ 10:36 am } · { Problem }
{ } · { Comments (22) }

!

In the above figure, the rectangle at the corner measures 6 cm x 12 cm. What is the area of the circle?

Pipes [Answered]

{ September 7, 2009 @ 4:12 am } · { Solution }
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Answer:

21 hours and 36 minutes. The exact size of the pipes and reservoir does not matter. If we label the large pipes L, the small pipes S and if the reservior has a total of T litres, then:

T / 6L = 12 which means L = T / 72

and

T / (3L + 9S) = 8 which means that S = T / 108

we want

T / 5S which gives 108 / 5 hours = 21.6 hours = 21 hours and 36 minutes.

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EnasMohey

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Hebatalla

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Shreif Hassan