Question
Solution
Let the speed of B be x kmph ⇒ Time taken by B to cover 40 km = 40/x ⇒ Time taken by A = (40/x) + 2 So, the speed of A = (20x)/(20 + x)   ----(1) Distance = 80 km ⇒ Time taken by B to cover 80 km = 80/x   ----(2) ⇒ Speed of A when he doubles his speed = (40x)/(20 + x) ⇒ Time taken by A to cover 80 km = (40 + 2x)/(x)   ----(3) A.T.Q., From (2) and (3) (80/x) + (3/2) = (40 + 2x)/x ⇒ (40 + 2x)/2x - 80/x = 3/2 ⇒ 2 (40 + 2x - 80) = 3x ⇒ 2 (2x - 40) = 3x ⇒ 4x - 80 = 3x ⇒ 4x - 3x = 80 ⇒ x = 80 ⇒ Speed of B = 80 kmph Distance = 90 km Time taken by B = 90/80 = 1(1/8) hrs
Pipe 'C' alone takes 5 more hours to fill the tank than the time taken by pipe 'C' and pipe 'D' together. Find the approximate ti...
Pipe A can fill a tank in 3 hours and Pipe B can fill the same tank in 6 hours. If both pipes are opened together, in how many hours will the tank be fi...
Time taken by pipe 'A' to fill a tank is 30 minutes. When both pipes 'A' and 'B' are opened together, the tank gets filled in 10 minutes. Find the time...
Pipe 'X' and 'Y' can fill a tank in 1 hour and 1 hour 30 minutes respectively. 'X' is opened alone. After 18 minutes, 'X' is closed and 'Y' is opened. ...
- Pipe 'A' can fill a tank in 18 hours. Pipe 'B' is ____% as efficient as pipe 'A'. If both pipes are opened simultaneously, the tank will be completely full...
Three pipes A, B, and C can fill a tank in 50 minutes, 60 minutes, and 75 minutes respectively. All are opened together. A is closed after 'n' minutes, ...
Two inlet pipes M and N alone can fill a tank in 12 hours and 16 hours respectively and an outlet pipe P alone can empty the whole tank in 8 hours. Firs...
Pipe A can fill a cistern in 18 hours. Pipes A and B together can fill it in 12 hours, while Pipes B and C together can fill it in 9 hours. In how many ...
A tank can be filled by two pipes, A and B, in 15 minutes and 20 minutes, respectively. Both pipes are opened together, but after 5 minutes, pipe A is c...
Pipe ‘A’ can fill a tank in 10 hours while pipe ‘B’ can empty it in 12 hours. They were operated on alternate hours starting with pipe ‘A’. ...
Relevant for Exams:
