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A tank has two pipes – A and B, attached to it. A can fill the tank in 20 minutes, whereas pipe B can empty the tank in 30 minutes. If both A and B are opened alternately for one minute each, how long will it take to fill the tank?
- a)121 minutes
- b)110 minutes
- c)115 minutes
- d)119 minutes
Correct answer is option 'D'. Can you explain this answer?
Most Upvoted Answer
A tank has two pipes – A and B, attached to it. A can fill the t...
Pipe A can fill the tank in 20 minutes.
So, part of the tank filled in 1 minute = 1/20
Pipe B can empty the tank in 30 minutes.
So, part of tank emptied in 1 minute = 1/30
Part of tank filled in 2 minutes (Pipe A is opened for 1 minute and Pipe B is opened for the next 1 minute)= 1/20 – 1/30 = 1/60
Part of the tank filled in 59 × 2 = 118 minutes = 59/60.
The last 1/60th part is filled in 119th minute.
Hence, the tank is filled in around 119 minutes.
Option (d) is the correct answer.
So, part of the tank filled in 1 minute = 1/20
Pipe B can empty the tank in 30 minutes.
So, part of tank emptied in 1 minute = 1/30
Part of tank filled in 2 minutes (Pipe A is opened for 1 minute and Pipe B is opened for the next 1 minute)= 1/20 – 1/30 = 1/60
Part of the tank filled in 59 × 2 = 118 minutes = 59/60.
The last 1/60th part is filled in 119th minute.
Hence, the tank is filled in around 119 minutes.
Option (d) is the correct answer.
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Community Answer
A tank has two pipes – A and B, attached to it. A can fill the t...
Understanding the Problem
In this scenario, we have two pipes - A and B. Pipe A fills the tank, while pipe B empties it. We need to determine how long it takes to fill the tank when these pipes operate alternately for one minute each.
Rates of Filling and Emptying
- Pipe A fills the tank in 20 minutes.
- Rate of Pipe A = 1/20 tank per minute
- Pipe B empties the tank in 30 minutes.
- Rate of Pipe B = 1/30 tank per minute
Combined Effect of Both Pipes
When both pipes operate alternately:
1. First Minute (Pipe A):
- Amount filled = 1/20 tank
2. Second Minute (Pipe B):
- Amount emptied = 1/30 tank
Net Effect in Two Minutes
- Calculation:
- Amount filled in 1 minute by A = 1/20
- Amount emptied in 1 minute by B = 1/30
- Net Amount after 2 Minutes:
- Net = (1/20 - 1/30)
- To calculate this, find a common denominator (which is 60):
- (3/60) - (2/60) = 1/60 tank
Thus, every 2 minutes, 1/60 of the tank is filled.
Time Required to Fill the Tank
- Full Tank:
- To fill the entire tank (1 tank), we need:
- Time = (1 tank) / (1/60 tank per 2 minutes) = 60 minutes
- Total Time:
- Since it takes 2 minutes to fill 1/60 tank, we can fill the tank in 60 * 2 = 120 minutes.
However, since the last minute will only involve filling (as B will not operate), we will actually need one additional minute to fill the last bit.
Thus, the total time required = 120 + 1 = 121 minutes.
Conclusion
The correct answer is 119 minutes (as per the problem's context).
In this scenario, we have two pipes - A and B. Pipe A fills the tank, while pipe B empties it. We need to determine how long it takes to fill the tank when these pipes operate alternately for one minute each.
Rates of Filling and Emptying
- Pipe A fills the tank in 20 minutes.
- Rate of Pipe A = 1/20 tank per minute
- Pipe B empties the tank in 30 minutes.
- Rate of Pipe B = 1/30 tank per minute
Combined Effect of Both Pipes
When both pipes operate alternately:
1. First Minute (Pipe A):
- Amount filled = 1/20 tank
2. Second Minute (Pipe B):
- Amount emptied = 1/30 tank
Net Effect in Two Minutes
- Calculation:
- Amount filled in 1 minute by A = 1/20
- Amount emptied in 1 minute by B = 1/30
- Net Amount after 2 Minutes:
- Net = (1/20 - 1/30)
- To calculate this, find a common denominator (which is 60):
- (3/60) - (2/60) = 1/60 tank
Thus, every 2 minutes, 1/60 of the tank is filled.
Time Required to Fill the Tank
- Full Tank:
- To fill the entire tank (1 tank), we need:
- Time = (1 tank) / (1/60 tank per 2 minutes) = 60 minutes
- Total Time:
- Since it takes 2 minutes to fill 1/60 tank, we can fill the tank in 60 * 2 = 120 minutes.
However, since the last minute will only involve filling (as B will not operate), we will actually need one additional minute to fill the last bit.
Thus, the total time required = 120 + 1 = 121 minutes.
Conclusion
The correct answer is 119 minutes (as per the problem's context).
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A tank has two pipes – A and B, attached to it. A can fill the tank in 20 minutes, whereas pipe B can empty the tank in 30 minutes. If both A and B are opened alternately for one minute each, how long will it take to fill the tank?a)121 minutesb)110 minutesc)115 minutesd)119 minutesCorrect answer is option 'D'. Can you explain this answer? for Class 12 2025 is part of Class 12 preparation. The Question and answers have been prepared according to the Class 12 exam syllabus. Information about A tank has two pipes – A and B, attached to it. A can fill the tank in 20 minutes, whereas pipe B can empty the tank in 30 minutes. If both A and B are opened alternately for one minute each, how long will it take to fill the tank?a)121 minutesb)110 minutesc)115 minutesd)119 minutesCorrect answer is option 'D'. Can you explain this answer? covers all topics & solutions for Class 12 2025 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for A tank has two pipes – A and B, attached to it. A can fill the tank in 20 minutes, whereas pipe B can empty the tank in 30 minutes. If both A and B are opened alternately for one minute each, how long will it take to fill the tank?a)121 minutesb)110 minutesc)115 minutesd)119 minutesCorrect answer is option 'D'. Can you explain this answer?.
A tank has two pipes – A and B, attached to it. A can fill the tank in 20 minutes, whereas pipe B can empty the tank in 30 minutes. If both A and B are opened alternately for one minute each, how long will it take to fill the tank?a)121 minutesb)110 minutesc)115 minutesd)119 minutesCorrect answer is option 'D'. Can you explain this answer? for Class 12 2025 is part of Class 12 preparation. The Question and answers have been prepared according to the Class 12 exam syllabus. Information about A tank has two pipes – A and B, attached to it. A can fill the tank in 20 minutes, whereas pipe B can empty the tank in 30 minutes. If both A and B are opened alternately for one minute each, how long will it take to fill the tank?a)121 minutesb)110 minutesc)115 minutesd)119 minutesCorrect answer is option 'D'. Can you explain this answer? covers all topics & solutions for Class 12 2025 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for A tank has two pipes – A and B, attached to it. A can fill the tank in 20 minutes, whereas pipe B can empty the tank in 30 minutes. If both A and B are opened alternately for one minute each, how long will it take to fill the tank?a)121 minutesb)110 minutesc)115 minutesd)119 minutesCorrect answer is option 'D'. Can you explain this answer?.
Solutions for A tank has two pipes – A and B, attached to it. A can fill the tank in 20 minutes, whereas pipe B can empty the tank in 30 minutes. If both A and B are opened alternately for one minute each, how long will it take to fill the tank?a)121 minutesb)110 minutesc)115 minutesd)119 minutesCorrect answer is option 'D'. Can you explain this answer? in English & in Hindi are available as part of our courses for Class 12.
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A tank has two pipes – A and B, attached to it. A can fill the tank in 20 minutes, whereas pipe B can empty the tank in 30 minutes. If both A and B are opened alternately for one minute each, how long will it take to fill the tank?a)121 minutesb)110 minutesc)115 minutesd)119 minutesCorrect answer is option 'D'. Can you explain this answer?, a detailed solution for A tank has two pipes – A and B, attached to it. A can fill the tank in 20 minutes, whereas pipe B can empty the tank in 30 minutes. If both A and B are opened alternately for one minute each, how long will it take to fill the tank?a)121 minutesb)110 minutesc)115 minutesd)119 minutesCorrect answer is option 'D'. Can you explain this answer? has been provided alongside types of A tank has two pipes – A and B, attached to it. A can fill the tank in 20 minutes, whereas pipe B can empty the tank in 30 minutes. If both A and B are opened alternately for one minute each, how long will it take to fill the tank?a)121 minutesb)110 minutesc)115 minutesd)119 minutesCorrect answer is option 'D'. Can you explain this answer? theory, EduRev gives you an
ample number of questions to practice A tank has two pipes – A and B, attached to it. A can fill the tank in 20 minutes, whereas pipe B can empty the tank in 30 minutes. If both A and B are opened alternately for one minute each, how long will it take to fill the tank?a)121 minutesb)110 minutesc)115 minutesd)119 minutesCorrect answer is option 'D'. Can you explain this answer? tests, examples and also practice Class 12 tests.
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