# Question #3285c

Sep 27, 2016

$x = 25 g$

#### Explanation:

The initial mass of the solution was 100g
As 50% (w/w) solute was present in 100g solution , we can say the mass of the solute in initial solution was 50g

After addition of x g solute in 100g solution the changed mass of solution became (x+100)g and total amount of solute became (x+50)g.
So the percentage of solute in final solution became 60%.

So

$\frac{x + 50}{x + 100} \times 100 = 60$

$\implies \frac{x + 50}{x + 100} = \frac{60}{100} = 0.6$

$\implies x + 50 = 0.6 \left(x + 100\right)$

$\implies x + 50 = 0.6 x + 60$

$\implies x - 0.6 x = 60 - 50$

$\implies 0.4 x = 10$

$\implies x = \frac{10}{0.4} = 25$