A pipe can fill an empty tank in 8 h. After it is kept open for 2 h, another pipe which can fill the tank in 6 h is opened. In how many more hours will the tank be filled?

A pipe can fill an empty tank in 8 h. After it is kept open for 2 h, a

1.	A pipe can fill an empty tank in 8 h. After it is kept open for 2 h, another pipe which can fill the tank in 6 h is opened. In how many more hours will the tank be filled?
Answer» `(18)/(7)h` `(19)/(7)h` `(19)/(9)h` `(18)/(8)h` Solution :Part of the tank filled in 2h `=(1)/(8) xx 2 = (1)/(4).` The part of tank to be filled. `=1-(1)/(4) = (3)/(4).` Part of tank filled in 1 h by both of the PIPES = `(1)/(8) + (1)/(6) = (7)/(24).` `therefore " Time taken to FILL "(3)/(4)` th of the tank by both the pipes. `=(3)/(4) xx (24)/(7) = (18)/(7)`h Hence, the correct OPTION is (a).