SOLUTION: Two pipes can fill a tank in 15 minutes if both are turned on. If only one is used, it would take 25 minutes longer for the smaller pipe to fill the tank than the larger pipe. How

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Question 816156: Two pipes can fill a tank in 15 minutes if both are turned on. If only one is used, it would take 25 minutes longer for the smaller pipe to fill the tank than the larger pipe. How long will it take for the smaller pipe to fill the tank?
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Add their individual rates of filling
to get their rate filling together
Let +t+ = time in minutes for
the larger pipe to fill the tank
+t+%2B+25+ = time in minutes for
the smaller pipe to fill tank
----------------------------------
( 1 tank filled / t min ) + ( 1 tank filled ) / t+25 min ) =
( 1 tank filled / 15 min )
+1%2Ft+%2B+1%2F%28+t%2B25+%29+=+1%2F15+
Multiply both sides by +15%2At%2A%28+t%2B25+%29+
+15%2A%28+t%2B25+%29+%2B+15t+=+t%2A%28+t%2B25+%29+
+15t+%2B+15%2A25+%2B+15t+=+t%5E2+%2B+25t+
+30t+%2B+375+=+t%5E2+%2B+25t+
+t%5E2+-+5t+-+375+=+0+
x+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+
+a+=+1+
+b+=+-5+
+c+=+-375+
x+=+%28-%28-5%29+%2B-+sqrt%28+%28-5%29%5E2-4%2A1%2A%28-375%29+%29%29%2F%282%2A1%29+
x+=+%28+5+%2B-+sqrt%28+25+%2B+1500+%29%29+%2F+2+
x+=+%28+5+%2B-+sqrt%28+1525+%29%29+%2F+2+
You can finish- I don't have calculator