46. Three pipes A, B and C can fill a tank in 6 hours, 9 hours and 12 hours respectively. B and C are opened for half an hour, then A is also opened. The time taken by the three pipes together to fill the remaining part of the tank is

1. 1. 3 hours
      

   
   
   

   2. 2 hours

   
   
   

   3. 2	1	hours
      	2

   
   
   

   4. 3	1	hours
      	2

   
   
   

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1. View Hint View Answer Discuss in Forum

   Given in question ,
   

   Part of the tank filled by B and C in half an hour =	1		1	+	1
   	2		9		12

   
   

   Part of the tank filled by B and C in half an hour =	1		4 + 3		=	7
   	2		36			72

   
   

   Remaining part = 1 -	7	=	72 - 7	=	65
   	72		72		72

   
   

   Part of tank filled by three pipes in an hour =	1	+	1	+	1
   	6		9		12

   
   

   Part of tank filled by three pipes in an hour =	6 + 4 + 3	=	13
   	36		36

   
   

   Correct Option: C

   Given in question ,
   

   Part of the tank filled by B and C in half an hour =	1		1	+	1
   	2		9		12

   
   

   Part of the tank filled by B and C in half an hour =	1		4 + 3		=	7
   	2		36			72

   
   

   Remaining part = 1 -	7	=	72 - 7	=	65
   	72		72		72

   
   

   Part of tank filled by three pipes in an hour =	1	+	1	+	1
   	6		9		12

   
   

   Part of tank filled by three pipes in an hour =	6 + 4 + 3	=	13
   	36		36

   
   

   ∴ Time to fill remaining part =	65	×	36	=	5	= 2	1	hours.
   	72		13		2		2

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47. Two pipes A and B can separately fill a tank in 2 hours and 3 hours respectively. If both the pipes are opened simultaneously in the empty tank, then the tank will be filled in
    

1. 1. 1 hour 12 minutes
      

   
   
   

   2. 2 hours 30 minutes
      

   
   
   

   3. 1 hour 15 minutes
      

   
   
   

   4. 1 hour 20 minutes

   
   
   

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1. View Hint View Answer Discuss in Forum

   On the basis of given details in question ,
   

   Part of tank filled by pipes A and B in 1 hour =	1	+	1	=	3 + 2	=	5	part
   	2		3		6		6

   
   

   ∴ Required time =	6	hours
   	5

   
   

   Correct Option: A

   On the basis of given details in question ,
   

   Part of tank filled by pipes A and B in 1 hour =	1	+	1	=	3 + 2	=	5	part
   	2		3		6		6

   
   

   ∴ Required time =	6	hours
   	5

   
   

   Required time = 1 hour	1	× 60
   	5

   
   Required time = 1 hour 12 minutes

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48. A pipe can fill a tank in x hours and another can empty it in y hours. They can together fill it in (y > x)

1. 1. xy	hours
      y - x

   
   
   

   2. x – y hours
      

   
   
   

   3. y – x hours

   
   
   

   4. xy	hours
      x - y

   
   
   

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1. View Hint View Answer Discuss in Forum

   When both pipes are opened simultaneously,
   

   Part of the tank filled in 1 hour =	1	-	1	=	y - x
   	x		y		xy

   
   

   Correct Option: A

   When both pipes are opened simultaneously,
   

   Part of the tank filled in 1 hour =	1	-	1	=	y - x
   	x		y		xy

   
   

   ∴ Required time =	xy	hours
   	y - x

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49. Pipe A can fill an empty tank in 6 hours and pipe B in 8 hours. If both the pipes are opened and after 2 hours pipe. A is closed, how much time B will take to fill the remaining tank?
    

1. 1. 7	1	hours
      	2

   
   
   

   2. 2	2	hours
      	5

   
   
   

   3. 2	1	hours
      	3

   
   
   

   4. 3	1	hours
      	3

   
   
   

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1. View Hint View Answer Discuss in Forum

   As per the given in question , we have
   

   Part of tank filled by pipes A and B in 2 hours = 2		1	+	1
   		6		8

   
   

   Part of tank filled by pipes A and B in 2 hours = 2		4 + 3		=	7
   		24			12

   
   

   Remaining part = 1 –	7	=	5
   	12		12

   
   This part is filled by pipe B.
   

   ∴ Required time =	5	× 8
   	12

   
   

   Correct Option: D

   As per the given in question , we have
   

   Part of tank filled by pipes A and B in 2 hours = 2		1	+	1
   		6		8

   
   

   Part of tank filled by pipes A and B in 2 hours = 2		4 + 3		=	7
   		24			12

   
   

   Remaining part = 1 –	7	=	5
   	12		12

   
   This part is filled by pipe B.
   

   ∴ Required time =	5	× 8
   	12

   
   

   Required time =	10	hours	= 3	1	hours
   	3			3

   
   

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50. If 1/3 of a tank holds 80 litres of water, then the quantity of water that 1/2 tank holds is:
    

1. 1. 240 litres
      

   
   
   

   2. 120 litres
      

   
   
   

   3. 80/3 litres
      

   
   
   

   4. 100 litres

   
   
   

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1. View Hint View Answer Discuss in Forum

   Let the capacity of the tank be q litres , then
   According to question ,
   

   	q	= 80
   	3

   
   ∴ q = 240
   

   Correct Option: B

   Let the capacity of the tank be q litres , then
   According to question ,
   

   	q	= 80
   	3

   
   ∴ q = 240
   

   ∴	q	=	240	= 120 litres
   	2		2

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