400gm solution has 40% salt in it. How much salt must be added to make it 50% in the solution?

Question

400gm solution has 40% salt in it. How much salt must be added to make it 50% in the solution?

Answer 1

s = amount of salt added.

 

400 + s = (400 + s)                         This is the weight

0.40(400) + 1.00s = 0.50(400 + s)    This is the solution

 

4(400) + 10s = 5((400 + s)

1600 + 10s = 2000 + 5s

5s = 400

s = 80