Its been awhile since I've dabbled in chemistry, but i do know that A isnt the answer because the question says solution, not mixture. This looks somewhat like a trick question, it says individual components, so the answer would be C. This is because the individual components do react to form a compound. B and D would be true if it didnt say individual components, so the question is basically focusing on only one ingredient, not the whole solution. Answer: C
150/30 = 5
HF1 20/2 = 10
HF2 10/2 = 5
HF3 5/2 = 2.5
HF4 2.5/2 = 1.25
HF5 1.25/2 = 0.625
Answer: 0.63g
The answer will be 17.9 grams