Aptitude - Alligation or Mixture - Discussion

Great surendra reddy.

The first one itself is short solution.
as we assume total soln as 8litre
so if x litre of water is added by replacing
So net water remains is 3-3x/8+x in 8 litre
and syrup is 5-5x/8
equalize both as both becomes equal in content aftr previous replacement.

we get x=8/5
but this is replecement if we assume cotent of vessel =8l
so part of replcement=replced amount/total amount
this means (8/5)/8 = 1/5 ans

I am getting 8/5 as the amount to be replaced. If there is 8litres of the total liquid then 3 litres is water and 5 litres is syrup. Now suppose if you remove x litres of the liquid the remaining liquid is 8-x.

In this 8-x, 3/8(8-x) is water and 5/8(8-x) is syrup.
Now if we add x litres of water to it the equation we get is
3/8(8-x)+x=5/8(8-x) since both the syrup and the liquid equals 4/8

Solving this equation we get x=8/5

Where did 1/5 come from? Please somebody explain. I am highly confused.

Thanks ameer.

I think amir done good solution.

40% of 8 parts is 3.2 and 60% is 4.8 how it's possible to get them as 3 and 5 as this is a big difference .

Why is that nthey got 1/5 only becoz syrup is considered?
w s
3 5
+1 -1
4 4

So 1/5 is correct, right? why not 1/3?

Water contains 3 parts and Syrup contains 5 parts, so total there are 8 parts there in the vessel.
now as asked , that in final mixture both water and syrup should be present half-half i.e 4 parts of water and 4 parts of syrup.

water syrup
initial- l3 5
final- 4 4

so,
final amount=initial amount(1-amount tobe replaced/total amount)

Note: here u should take syrup's amount not water.(If the question would be, to replace the mixture with syrup then take water's amount.

4=5(1-K/8),
K=8/5

Most questions u can solve by this , but i did not get how they got 1/5 as an answer.

Thank you kiran.

Good victor.