From a 20lt solution of alt and water with 20% salt, 2lt of water is evaporated. Find the new % concentration of salt.
a. 20%             b. 23%                         c. 25%             d. None


In 20lt, salt = 20% => 4 lt.
New volume = 18 lt (2 lt evaporated)
So, new % = 4/18 X 100 = 22.22%