Two pipes running together can fill a cistern in 2811 minutes. If one pipe takes one minutemore than the other to fill the cistern, find the sum of individual time in which each pipe will fill the cistern.
11 min
Let Ist pipe fills the cistern in x minIInd pipe will fill the cistern in=(x+1)minAccording to the question,1x+1x+1=1130 ⇒x+1+xx(x+1)=1130⇒ 2x+1x2+x=1130⇒ 11x2+11x=60x+3011x2+11x−60x−30=011x2−49x−30=011x2−55x+6x−30=0⇒ 11x(x−5)+6(x−5)=0(x−5)(11x+6)=0⇒ x=5,−6/11;x=−6/11(neglected)So, time taken by the pipes to fill the cistern=5 min.(5+1)=6min.
So, the sum of individual time of each pipe =(5+6) mins=11 mins