Question

How much water should we add to 20 kg of seawater to change its concentration from 3% to 2%?

Answer 1

Answer:

10 kg

Step-by-step explanation:

In 3% concentration of 20 kg of seawater, there will be $\frac{20 \times 3}{100} = 0.6$ kg of salt.

So, if it is a 2% solution of seawater,

Then 2 kg salt will be there in 100 kg solution.

So, 0.6 kg salt will be there in $\frac{100 \times 0.6}{2}= 30$ kg of solution.

So, to make a solution from 3% to 2% we have to add (30 - 20) = 10 kg of water with a 20 kg solution. (Answer)