Pipe A can fill a tank in 6 hours, pipe B can fill the same tank in 28 hours and pipe C can fill the same tank in 21 hours. The time taken (in hours) by them to fill one-fourth of the same tank if they operate together is:
1
Take the capacity of the tank as the LCM of 6, 28 and 21, which is 84 units.
Then pipe A fills 84 ÷ 6 = 14 units per hour, pipe B fills 84 ÷ 28 = 3 units per hour and pipe C fills 84 ÷ 21 = 4 units per hour.
Working together they fill 14 + 3 + 4 = 21 units per hour.
One-fourth of the tank is 84 ÷ 4 = 21 units, which takes 21 ÷ 21 = 1 hour.
Hence, the answer is 1.
Similar Questions
One pipe can fill a tank in 6 minutes, while another pipe can empty the completely filled tank in 9 minutes. If both the pipes are opened together when the tank is empty, how many minutes will it take to fill one-half of the tank?
Pipe A can fill a tank in 6 hours, pipe B can fill the same tank in 36 hours and pipe C can fill the same tank in 18 hours. The time taken (in hours) by them to fill one-fourth of the same tank if they operate together is:
Pipe A can fill a tank in 4 hours, pipe B can fill the same tank in 6 hours and pipe C can fill the same tank in 12 hours. The time taken (in hours) by them to fill half of the same tank if they operate together is:
Pipe A can fill a tank in 6 hours, pipe B can fill the same tank in 21 hours and pipe C can fill the same tank in 28 hours. The time taken (in hours) by them to fill one-fourth of the same tank if they operate together is:
Pipe A can fill a tank in 6 hours, pipe B can fill the same tank in 30 hours and pipe C can fill the same tank in 20 hours. The time taken (in hours) by them to fill one-fourth of the same tank if they operate together is:
Pipe A can fill a tank in 4 hours, pipe B can fill the same tank in 8 hours and pipe C can fill the same tank in 8 hours. The time taken (in hours) by them to fill half of the same tank if they operate together is:
Pipe A can fill a tank in 6 hours, pipe B can fill the same tank in 48 hours and pipe C can fill the same tank in 16 hours. The time taken (in hours) by them to fill one-fourth of the same tank if they operate together is:
Pipe A can fill a tank in 3 hours, pipe B can fill the same tank in 24 hours and pipe C can fill the same tank in 8 hours. The time taken (in hours) by them to fill half of the same tank if they operate together is:
Pipe A can fill a tank in 3 hours, pipe B can fill the same tank in 15 hours and pipe C can fill the same tank in 10 hours. The time taken (in hours) by them to fill half of the same tank if they operate together is:1190
Pipe A can fill a tank in 3 hours, pipe B can fill the same tank in 10 hours and pipe C can fill the same tank in 15 hours. The time taken (in hours) by them to fill half of the same tank if they operate together is:1188
Important Questions from Pipe and Cistern
Pipe P can fill $\frac{2}{3}$ part of a tank in 16 hours, and pipe Q can fill $\frac{5}{6}$ part of the same tank in 20 hours. Both P and Q were kept open for 2 hours, then both were closed. Pipe R alone was then opened and it emptied the water in the tank in 8 hours. Pipes P, Q and R together can fill the empty tank in:
- Pipe A can fill a tank in 18 hours, pipe B can fill the same tank in 30 hours and pipe C can fill the same tank in 18 hours. The time taken by them to fill the same tank if they operate together is::
Pipe P can fill $\frac{2}{3}$ part of a tank in 24 hours, and pipe Q can fill $\frac{2}{3}$ part of the same tank in 16 hours. Both P and Q were kept open for 4 hours, then both were closed. Pipe R alone was then opened and it emptied the water in the tank in 5 hours. Pipes P, Q and R together can fill the empty tank in:
- Pipe P can fill $\frac{5}{7}$ part of a tank in 30 hours, and pipe Q can fill $\frac{2}{5}$ part of the same tank in 28 hours. Both P and Q were kept open for 7 hours, then both were closed. Pipe R alone was then opened and it emptied the water in the tank in 8 hours. Pipes P, Q and R together can fill the empty tank in:
Pipe P can fill $\frac{3}{8}$ part of a tank in 21 hours and pipe Q can fill $\frac{2}{7}$ part of the same tank in 16 hours. Both P and Q were kept open for 2 hours, then both were closed. Pipe R alone was then opened and it emptied the water in the tank in 3 hours. Pipes P, Q and R together can fill the empty tank in:
