Correct option is A)
Let x be the weights, in Kilograms, of pure water to be added. Let y be the weight, in Kilograms, of the 10% solution.
Let us now express the fact that the amount of salt in the pure water (which is 0) plus the amount of salt in the 30% solution is equal to the amount of salt in the final saline solution at 10%.
0 + 30% 100 = 10%y
Now by substituting the value of y in terms of x, we get the equation as,
30% 100 = 10%(x+100)
Answer x=200 Kilograms.