document.write( "Question 1177723: It takes pump A 2 hours less time than pump B to empty a pool. Pump A is started at 8:00am and pump B at 10:00am. At 12:00pm 60% of the pool.is empty when pump B broke down. How much time after 12:00pm would it take pump A to empty the pool? \n" ); document.write( "
Algebra.Com's Answer #806852 by greenestamps(13200)![]() ![]() You can put this solution on YOUR website! \n" ); document.write( "let x = # hours A takes alone to empty the pool \n" ); document.write( "then x+2 = # hours B takes alone \n" ); document.write( "1/x = fraction of job A does in 1 hour \n" ); document.write( "1(x+2) = fraction of job B does in 1 hour \n" ); document.write( "At 12pm when pump B broke down, A has been working 4 hours and B 2 hours. The fraction of the job done at that time is \n" ); document.write( " \n" ); document.write( "That fraction of the job done at 12pm is 60% = 3/5. Solve that equation to find out how many hours A takes to empty the pool alone. \n" ); document.write( " \n" ); document.write( "Multiply through by the least common denominator \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "This does not factor; use the quadratic formula and of course use the positive root. \n" ); document.write( " \n" ); document.write( "2/5 of the pool remains to be emptied; the number of hours it will take A to finish is \n" ); document.write( " \n" ); document.write( "ANSWER: to a few decimal places, 3.7664 hours \r \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " |