This problem involves finding the time it takes for multiple pipes operating simultaneously to fill a tank, given their individual filling times.
First, determine the rate at which each pipe fills the tank. The rate is the fraction of the tank filled per hour.
To find the combined rate when all pipes operate together, add their individual rates.
Combined Rate = Rate A + Rate B + Rate C
Combined Rate = $\frac{1}{19} + \frac{1}{21} + \frac{1}{8}$
Find a common denominator, which is the least common multiple (LCM) of 19, 21, and 8. LCM(19, 21, 8) = $19 \times 21 \times 8 = 3192$.
Combined Rate = $\frac{1 \times (21 \times 8)}{19 \times 21 \times 8} + \frac{1 \times (19 \times 8)}{19 \times 21 \times 8} + \frac{1 \times (19 \times 21)}{19 \times 21 \times 8}$
Combined Rate = $\frac{168}{3192} + \frac{152}{3192} + \frac{399}{3192}$
Combined Rate = $\frac{168 + 152 + 399}{3192} = \frac{719}{3192}$ tank per hour.
The time taken to fill the tank together is the reciprocal of the combined rate.
Time = $\frac{1}{\text{Combined Rate}}$
Time = $\frac{1}{\frac{719}{3192}} = \frac{3192}{719}$ hours.
Convert the improper fraction $\frac{3192}{719}$ into a mixed number.
Divide 3192 by 719:
$3192 \div 719 = 4$ with a remainder of $3192 - (4 \times 719) = 3192 - 2876 = 316$.
Therefore, the time taken is $4 \frac{316}{719}$ hours.
A pipe can fill a cistern in 20 minutes where as the cistern when full can be emptied by a leak in 28 minutes. When both are opened, The time taken to fill the cistern is:
‘A’ pipe can empty a tank in 20 minutes. The second pipe ‘B’ has a diameter twice as that of ‘A’. If both A & B pipe are attached to the tank how much time will be required to empty the tank?
Pipes A and B can empty a full tank in 16 hours and 24 hours, respectively. Pipe C alone can fill the empty tank in 4 hours. If A, B and C are opened together, the tank will be 35% full after :
Pipes A and B can fill a tank in 36 minutes and 45 minutes, respectively. Both these pipes were opened simultaneously. After 20 minutes, a leak at the bottom of the tank was spotted which was immediately sealed. The tank was full in another 15 minutes. The leak alone can empty the full tank in:
A cistern has a leak which would empty it in 6 hours. A tap is turned on which admits 10 litres of water per minute into the cistern. When it is full it is now emptied in 10 hours. What is the capacity (in litres) of the cistern?