Question

300 gms of salt solution has 40% salt in it. How much salt should be added to make it 50% in the solution?

• A. 40 gms
• B. 60 gms
• C. 70 gms
• D. 80 gms

Answer 1

The Correct Option is B

To solve this problem, we need to determine the amount of salt that should be added to a 300 g salt solution with 40% salt concentration to achieve a 50% salt concentration.

Given:

• Weight of the solution: 300 g
• Current concentration of salt: 40%
• Target concentration of salt: 50%

We start by calculating the initial amount of salt in the current solution:

Initial salt = (40/100) × 300 = 120 g

Let x be the amount of salt to be added. Once x grams of salt is added, the total salt in the solution becomes (120 + x) grams, while the total weight of the solution becomes (300 + x) grams.

We want the new concentration of salt to be 50%. Therefore, we set up the equation for the salt concentration after adding x grams of salt:

(120 + x)/(300 + x) = 50/100

Cross-multiply to solve for x:

(120 + x) = 0.5(300 + x)

120 + x = 150 + 0.5x

120 + x = 150 + 0.5x

Subtract 0.5x from both sides:

120 + 0.5x = 150

Subtract 120 from both sides:

0.5x = 30

Divide by 0.5:

x = 60

Thus, 60 grams of salt should be added to the solution to achieve a 50% concentration.

The correct answer is 60 gms.