Defence Exam > Defence Questions > Two taps P and Q can fill a tank in 12 hours,...
Start Learning for Free
Two taps P and Q can fill a tank in 12 hours, and 20 hours, respectively. If both the taps are opened simultaneously, after how much time Q should be closed so that the tank is full in 9 hours?
- a)4 hours
- b)6 hours
- c)5 hours
- d)8 hours
Correct answer is option 'C'. Can you explain this answer?
| FREE This question is part of | Download PDF Attempt this Test |
Verified Answer
Two taps P and Q can fill a tank in 12 hours, and 20 hours, respective...
GIVEN:
Tap P can fill the tank in 12 hours
Tap Q can fill the tank in 20 hours
Tap Q will be closed so that the tank is full in 9 hours
Tap P can fill the tank in 12 hours
Tap Q can fill the tank in 20 hours
Tap Q will be closed so that the tank is full in 9 hours
CALCULATION:
Let B be closed after x hours. Then,
Part filled by (P + Q) in x hours + part filled by P in (9 – x) hours = 1
x (1/12 + 1/20) + (9 – x) × 1/12 = 1
⇒ 2x/15 + (9 - x)/12 = 1
⇒ 8x + 5(9 – x) = 60
⇒ 3x = 15
∴ x = 5
∴ Hence, Q must be closed after 5 hours.
Let B be closed after x hours. Then,
Part filled by (P + Q) in x hours + part filled by P in (9 – x) hours = 1
x (1/12 + 1/20) + (9 – x) × 1/12 = 1
⇒ 2x/15 + (9 - x)/12 = 1
⇒ 8x + 5(9 – x) = 60
⇒ 3x = 15
∴ x = 5
∴ Hence, Q must be closed after 5 hours.
Most Upvoted Answer
Two taps P and Q can fill a tank in 12 hours, and 20 hours, respective...
To solve this problem, we can use the concept of work done.
Let's assume that the tank has a capacity of 1 unit (it could be any unit of measurement).
Given:
Tap P can fill the tank in 12 hours, so the work done by tap P in 1 hour is 1/12.
Tap Q can fill the tank in 20 hours, so the work done by tap Q in 1 hour is 1/20.
Work done by both taps together in 1 hour:
= work done by tap P + work done by tap Q
= 1/12 + 1/20
= (5 + 3)/60
= 8/60
= 2/15
Let's assume that Q needs to be closed after x hours.
Work done by both taps together in x hours:
= (work done by both taps together in 1 hour) * x
= (2/15) * x
= 2x/15
According to the given condition, the tank should be filled in 9 hours. So, the work done by both taps together in 9 hours is 1.
Therefore, we can set up the equation:
2x/15 = 1
Solving for x:
2x = 15
x = 15/2
x = 7.5
Since x represents the number of hours, and it is not possible to close a tap after half an hour, we need to round up to the nearest whole number. Therefore, Q should be closed after 8 hours.
Therefore, the correct answer is option 'D' - 8 hours.
Let's assume that the tank has a capacity of 1 unit (it could be any unit of measurement).
Given:
Tap P can fill the tank in 12 hours, so the work done by tap P in 1 hour is 1/12.
Tap Q can fill the tank in 20 hours, so the work done by tap Q in 1 hour is 1/20.
Work done by both taps together in 1 hour:
= work done by tap P + work done by tap Q
= 1/12 + 1/20
= (5 + 3)/60
= 8/60
= 2/15
Let's assume that Q needs to be closed after x hours.
Work done by both taps together in x hours:
= (work done by both taps together in 1 hour) * x
= (2/15) * x
= 2x/15
According to the given condition, the tank should be filled in 9 hours. So, the work done by both taps together in 9 hours is 1.
Therefore, we can set up the equation:
2x/15 = 1
Solving for x:
2x = 15
x = 15/2
x = 7.5
Since x represents the number of hours, and it is not possible to close a tap after half an hour, we need to round up to the nearest whole number. Therefore, Q should be closed after 8 hours.
Therefore, the correct answer is option 'D' - 8 hours.
|
Explore Courses for Defence exam
|
|
Similar Defence Doubts
Two taps P and Q can fill a tank in 12 hours, and 20 hours, respectively. If both the taps are opened simultaneously, after how much time Q should be closed so that the tank is full in 9 hours?a)4 hoursb)6 hoursc)5 hoursd)8 hoursCorrect answer is option 'C'. Can you explain this answer?
Question Description
Two taps P and Q can fill a tank in 12 hours, and 20 hours, respectively. If both the taps are opened simultaneously, after how much time Q should be closed so that the tank is full in 9 hours?a)4 hoursb)6 hoursc)5 hoursd)8 hoursCorrect answer is option 'C'. Can you explain this answer? for Defence 2024 is part of Defence preparation. The Question and answers have been prepared according to the Defence exam syllabus. Information about Two taps P and Q can fill a tank in 12 hours, and 20 hours, respectively. If both the taps are opened simultaneously, after how much time Q should be closed so that the tank is full in 9 hours?a)4 hoursb)6 hoursc)5 hoursd)8 hoursCorrect answer is option 'C'. Can you explain this answer? covers all topics & solutions for Defence 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for Two taps P and Q can fill a tank in 12 hours, and 20 hours, respectively. If both the taps are opened simultaneously, after how much time Q should be closed so that the tank is full in 9 hours?a)4 hoursb)6 hoursc)5 hoursd)8 hoursCorrect answer is option 'C'. Can you explain this answer?.
Two taps P and Q can fill a tank in 12 hours, and 20 hours, respectively. If both the taps are opened simultaneously, after how much time Q should be closed so that the tank is full in 9 hours?a)4 hoursb)6 hoursc)5 hoursd)8 hoursCorrect answer is option 'C'. Can you explain this answer? for Defence 2024 is part of Defence preparation. The Question and answers have been prepared according to the Defence exam syllabus. Information about Two taps P and Q can fill a tank in 12 hours, and 20 hours, respectively. If both the taps are opened simultaneously, after how much time Q should be closed so that the tank is full in 9 hours?a)4 hoursb)6 hoursc)5 hoursd)8 hoursCorrect answer is option 'C'. Can you explain this answer? covers all topics & solutions for Defence 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for Two taps P and Q can fill a tank in 12 hours, and 20 hours, respectively. If both the taps are opened simultaneously, after how much time Q should be closed so that the tank is full in 9 hours?a)4 hoursb)6 hoursc)5 hoursd)8 hoursCorrect answer is option 'C'. Can you explain this answer?.
Solutions for Two taps P and Q can fill a tank in 12 hours, and 20 hours, respectively. If both the taps are opened simultaneously, after how much time Q should be closed so that the tank is full in 9 hours?a)4 hoursb)6 hoursc)5 hoursd)8 hoursCorrect answer is option 'C'. Can you explain this answer? in English & in Hindi are available as part of our courses for Defence.
Download more important topics, notes, lectures and mock test series for Defence Exam by signing up for free.
Here you can find the meaning of Two taps P and Q can fill a tank in 12 hours, and 20 hours, respectively. If both the taps are opened simultaneously, after how much time Q should be closed so that the tank is full in 9 hours?a)4 hoursb)6 hoursc)5 hoursd)8 hoursCorrect answer is option 'C'. Can you explain this answer? defined & explained in the simplest way possible. Besides giving the explanation of
Two taps P and Q can fill a tank in 12 hours, and 20 hours, respectively. If both the taps are opened simultaneously, after how much time Q should be closed so that the tank is full in 9 hours?a)4 hoursb)6 hoursc)5 hoursd)8 hoursCorrect answer is option 'C'. Can you explain this answer?, a detailed solution for Two taps P and Q can fill a tank in 12 hours, and 20 hours, respectively. If both the taps are opened simultaneously, after how much time Q should be closed so that the tank is full in 9 hours?a)4 hoursb)6 hoursc)5 hoursd)8 hoursCorrect answer is option 'C'. Can you explain this answer? has been provided alongside types of Two taps P and Q can fill a tank in 12 hours, and 20 hours, respectively. If both the taps are opened simultaneously, after how much time Q should be closed so that the tank is full in 9 hours?a)4 hoursb)6 hoursc)5 hoursd)8 hoursCorrect answer is option 'C'. Can you explain this answer? theory, EduRev gives you an
ample number of questions to practice Two taps P and Q can fill a tank in 12 hours, and 20 hours, respectively. If both the taps are opened simultaneously, after how much time Q should be closed so that the tank is full in 9 hours?a)4 hoursb)6 hoursc)5 hoursd)8 hoursCorrect answer is option 'C'. Can you explain this answer? tests, examples and also practice Defence tests.
|
|
Explore Courses for Defence exam
|
|
Signup for Free!
Signup to see your scores go up within 7 days! Learn & Practice with 1000+ FREE Notes, Videos & Tests.
|
© EduRev
|
Education Revolution
|
Follow Us
|
Signup to see your scores
go up within 7 days!
Access 1000+ FREE Docs, Videos and Tests
Takes less than 10 seconds to signup