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two pipes a and b can fill a tank in 20 minutes and 30 minutes respectively . If initially only pipe b was kept open for 2/5th of the total time and both pipes a and b were kept open for the rest of the time then how many minutes would both pipes take to fill the tank |
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Answer» Step-by-step explanation: Pipe A 1 hr work=1/30 Pipe B 1 hr work=1/20 let total time required to FILL the tank =xhrs since pipe B is open for half hr so work done by pipe B in X/2 hrs =x/40hrs and work done by pipe (A+B) in remaining x/2 hrs=x/24hrs so total work done is =x/40+x/24 1=x/40+x/24 =>1=8x/120 =>120=8x so x=15hrslet x will be COMPLETION time so, x/2*(1/20) + x/2*(1/30 + 1/20)=1 8x=120 x=120/8 x=15 ans I hope it will help you to UNDERSTAND ❤ |
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