A vessel is filled with liquid, 3 parts of which are water and 5 parts syrup. How much of the mixture must be drawn off and replaced with water so that the mixture may be half water and half syrup?

Answer: Option C

Explanation:

Suppose the vessel initially contains 8 litres of liquid.

Let x litres of this liquid be replaced with water.

Quantity of water in new mixture =		3 -	3x	+ x		litres
			8

Quantity of syrup in new mixture =		5 -	5x		litres
			8

		3 -	3x	+ x		=		5 -	5x
			8						8

5x + 24 = 40 - 5x

10x = 16

x =	8	.
	5

So, part of the mixture replaced =		8	x	1		=	1	.
		5		8			5