SSC Selection Post Matric 20221)Pipes A and B together can fill an empty tank in 30 hours, whereas pipes B and C together can fill it in 24 hours. A, B and C together can fill the tank in 20 hours. In how many hours can pipe B alone fill 35% of the tank?
14
\({1 \over A}+{1 \over B} = {1 \over 30}\), \({1 \over B} + {1 \over C} = {1 \over 24}\), \({1 \over A}+{1 \over B} + {1 \over C} = {1 \over 20}\)
Solving above three equations we get A = 120hrs, B= 40hrs and C = 60hrs
Now for filling 35% of the tank by B alone we get, 35% of 60 = 21 hrs
SSC Selection Post Matric 20222)Pipes A and B can fill a tank in 4 hours and 6 hours 40 minutes, respectively; whereas a third pipe C can empty the full tank in 1 hours 40 minutes. A and B are opened at 2:00p.m. and 3:00 p.m., respectively and C is opened at 4:00 p.m. The tank will be completely empty at:
7:15 p. m.