Question

how many kg of pure salt must be added to 50kg of 4% solution of salt &water to increase it to a 10% solution

Answer 1

Step-by-step explanation:

Let's begin by writing expressions for the two input salt amounts and the final output salt amount:

input pure salt amount: (1.00)(x)

input 2% salt amount: (0.02)(30)

output 10% salt amount: (0.10)(x + 30)

Next, let's write an equation to express the combining the two input salt amounts to produce the final output salt amount and then solve that equation for our unknown pure salt amount (x):

(1.00)(x) + (0.02)(30) = (0.10)(x + 30)

x + 0.6 = 0.1x + 3

x - 0.1x = 3 - .6

0.9x = 2.4

x = 2.4/0.9

x = 8/3 kg pure salt