(B) Part of the tank filled by $A$ and $B$ in $1$ minute $= (1/18 + 1/9) = (1+2)/18 = 3/18 = 1/6$.Part of the tank filled by $A$ and $B$ in $4$ minute

Name: Exam Paper Generator | JEE NEET Paper Generator | Vedclass
Brand: Vedclass
Rating: 5 (35 reviews)

(B) Part of the tank filled by $A$ and $B$ in $1$ minute $= (1/18 + 1/9) = (1+2)/18 = 3/18 = 1/6$.Part of the tank filled by $A$ and $B$ in $4$ minutes $= 4 \times (1/6) = 2/3$.When $A, B,$ and $C$ are all open,the net rate of emptying the tank is $= (1/18 + 1/9) - 1/5 = 1/6 - 1/5 = (5-6)/30 = -1/30$.The negative sign indicates that the tank is being emptied at a rate of $1/30$ of the tank per minute.Time taken to empty the $2/3$ filled tank $= (2/3) / (1/30) = (2/3) \times 30 = 20$ minutes.

Competitive Quantitative Aptitude Pipes and Cistern Pipes and Cistern

Medium

Two pipes $A$ and $B$ can fill a cistern in $18$ $minutes$ and $9$ $minutes$ respectively,while a third pipe $C$ can empty the full tank in $5$ $minutes$. $A$ and $B$ are kept open for $4$ $minutes$ in the beginning and then $C$ is also opened. In what time (in $minutes$) is the cistern emptied?

A
$15$
B
$20$
C
$22$
D
$24$

Explore More

Browse All

Question Bank

All Subjects

Competitive Questions

Competitive

Quantitative Aptitude Questions

Chapter

Pipes and Cistern

Subtopic

Pipes and Cistern

$A$ pipe can empty a cistern in $27$ $hours$. Find the time (in $hours$) in which $\frac{2}{3}$ part of the cistern will be emptied?

Easy

View Solution

Two pipes can fill a cistern separately in $24$ $minutes$ and $40$ $minutes$ respectively. $A$ waste pipe can drain off $30 \text{ litres per minute}$. If all the three pipes are opened,the cistern fills in one $hour$. The capacity (in $litres$) of the cistern is:

Easy

View Solution

$A$ pipe can fill a tank with water in $5$ $hours$ and another pipe can empty the same tank in $4$ $hours$. If the tank is completely filled and both the taps are opened together,in how much time $(hours)$ will the tank be empty?

Easy

View Solution

$A$ tank is filled in $5$ $hours$ by three pipes $A, B$ and $C$. Pipe $C$ is twice as fast as $B,$ and $B$ is twice as fast as $A$. How much time (in $hours$) will pipe $A$ alone take to fill the tank?

Medium

View Solution

Two pipes $A$ and $B$ can fill a tank in $30$ $minutes$ and $45$ $minutes$ respectively. Pipe $C$ can empty the tank in $36$ $minutes$. Initially,pipes $A$ and $B$ are opened. After $12$ $minutes$,pipe $C$ is also opened. What is the total time (in $minutes$) required to fill the tank?

Easy

View Solution

Vedclass Products

For Students

Vedclass Test Series

Mock tests in real JEE/NEET style with performance analysis. 5-day free trial.

Start Free Trial

For Teachers

Exam Paper Generator

Generate Set A/B/C/D exam papers from 7.5L+ questions in 2 minutes. 3 chapters free.

Try Free

For Institutes

Online Exam Module

Live online exams with unlimited students, 360° analytics & white-label branding.

See Demo

Two pipes $A$ and $B$ can fill a cistern in $18$ $minutes$ and $9$ $minutes$ respectively,while a third pipe $C$ can empty the full tank in $5$ $minutes$. $A$ and $B$ are kept open for $4$ $minutes$ in the beginning and then $C$ is also opened. In what time (in $minutes$) is the cistern emptied?

Similar Questions

$A$ pipe can empty a cistern in $27$ $hours$. Find the time (in $hours$) in which $\frac{2}{3}$ part of the cistern will be emptied?

Two pipes can fill a cistern separately in $24$ $minutes$ and $40$ $minutes$ respectively. $A$ waste pipe can drain off $30 \text{ litres per minute}$. If all the three pipes are opened,the cistern fills in one $hour$. The capacity (in $litres$) of the cistern is:

$A$ pipe can fill a tank with water in $5$ $hours$ and another pipe can empty the same tank in $4$ $hours$. If the tank is completely filled and both the taps are opened together,in how much time $(hours)$ will the tank be empty?

$A$ tank is filled in $5$ $hours$ by three pipes $A, B$ and $C$. Pipe $C$ is twice as fast as $B,$ and $B$ is twice as fast as $A$. How much time (in $hours$) will pipe $A$ alone take to fill the tank?

Two pipes $A$ and $B$ can fill a tank in $30$ $minutes$ and $45$ $minutes$ respectively. Pipe $C$ can empty the tank in $36$ $minutes$. Initially,pipes $A$ and $B$ are opened. After $12$ $minutes$,pipe $C$ is also opened. What is the total time (in $minutes$) required to fill the tank?

Vedclass Test Series

Exam Paper Generator

Online Exam Module