shrestharaj wrote:
after following all the answers I found this method easy but I am not clear from where did you get 1 as concentration for added . Please explain me.
there is a similar problem but ratios are used.please explain this problem with the help of this method
Ques:
A vessel is filled with liquid ,3 parts of which are water and 5 parts syrup. How much of mixture must be drawn off and replaced with water so the mixture may be half water and half syrup?
Water ................... Syrup ............................ Total
3 .............................. 5 .................................. 8
\(3 - \frac{3x}{8}\) .................. \(5 - \frac{5x}{8}\) ............................ 8 - x (Say x litres of mixture is taken off)
\(3 - \frac{3x}{8} + x\) ................ \(5 - \frac{5x}{8}\) ......................... 8 (Say x litres of water is added; same as quantity of mixture removed)
Given that now the water content should be 50%, so setting up the equation accordingly
\(\frac{1}{2} * 8 = 3 - \frac{3x}{8} + x\)
\(\frac{5x}{8} = 1\)
\(x = \frac{8}{5}\)