Two pipes A and B can fill a cistern in 371 minutes and

Two pipes A and B can fill a cistern in 37 1 minutes and 45 minutes respectively. Both
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pipes are opened.The cistern will be filled just in half an hour, if the pipe B is turned off after :

On the basis of given details in question ,
Pipe A fills the tank in 75/2 minutes.

∴ Part of the tank filled by A in 30 minutes =	2	× 30 =	4
	75		5

Remaining part = 1 -	4	=	1
	5		5

Now, 1 part is filled by pipe B in 45 minutes

∴ 1 / 5 part is filled in = 45 ×	1	= 9 minutes
	5

Hence, the pipe B should be turned off after 9 minutes.

Two pipes A and B can fill a cistern in 37	1	minutes and 45 minutes respectively. Both
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