50 ml of water 100 ml of water 5 grams of salt 10 grams of salt
I gave my students this multiple choice question: David makes a solution by dissolving 10 grams of salt in 100 ml of water. He wants a solution that is half as concentrated. What should he add to the original solution to obtain a solution that is about half as concentrated?

Only one answer is correct among these 4 choices:
- 50 ml of water
- 100 ml of water
- 5 grams of salt
- 10 grams of salt

Could you tell me which one is correct?

100 ml of water