Question

In 6 liter water 5% salt will be evaporated now it is 4 liters wt is salt %

Answer 1

6 litre contains 5% salt

wt of salt = 6000 x 5 / 100 = 300 g

After evaporation the volume reduced to 4 litres

Now the salt content is 300 x 100 / 4000 = 30/4 = 7.5%