Question

300g of salt solution has 40% salt in it how much salt should be added to make it 50% in the solution

Answer 1

Amount of salt in solution = 300 × 40/100 = 120.
Let amount of salt to be added is X.

Then, total solution is 300 + X and amount of salt is 120 + X.
To make it 50%,

(300 + X) × 50/100 = (120 + X)
300 + X = 240 + 2X
X = 60/2 = 30 g

Answer 2

Amount of salt in solution = 300 × 40/100 = 120.

Let amount of salt to be added is X.

Then, total solution is 300 + X and amount of salt is 120 + X.

To make it 50%,

(300 + X) × 50/100 = (120 + X)

300 + X = 240 + 2X

X = 60/2 = 30 g