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2 pipes are used to fill pool. 1st pipe can fill the pool 6 hrs alone. two pipes can fill in 3 hrs less time than 2nd pipe. how long it will take for 2nd pipe

please helpppppp me. i dont know how to solved it.

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David W. | I'll help you understand math!I'll help you understand math!
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How much gets done per hour?
 
1/6 + 1/p = 1/(p - 3)
 
Once we find and apply the common denominator, 6p(p - 3), we only deal with the numerators.
 
p(p - 3) + 6(p - 3) = 6p
p2 - 3p + 6p - 18 = 6p
p2 - 3p - 18 = 0
(p - 6)(p + 3) = 0
 
p - 6 = 0
p = 6
 
p + 3 = 0
p = -3
Since we can't go back in time, we disregard this solution.
 
The 2nd pipe can also fill the pool in 6 hours alone.