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Question
6 pumps are required to fill a water sump in 1 hr 30 minutes. What will be the time taken to fill the sump if one pump is switched off?
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Solution
Let x be the required time taken
| Time taken in minutes | 1 hr. 30 m = 90 m | x |
| Number of pumps | 6 | 6 − 1 = 5 |
As the number of pumps increases the time taken to fill the sump will be less
∴ They are in inverse proportion
x1y1 = x2y2
90 × 6 = x × 5
1
`"60)"overline108("`
60
48
x = `(90 xx 6)/5`
= 108 minutes
= `108/60`
= 1 hr. 48 min
Time taken in minutes 1 hr. 48 m
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