A 200 mg/dl solution was diluted 1:10. This diluted solution was then additionally diluted 1:5. What us the concentration of the final dilution?

Answer 1

Isn't it diluted by a factor of 50?

Answer 2

The resulting concentration is 1/10 x 1/5 = 1/50 of the original. That would be 4 mg/dl

Answer 3

1/10x1/5= 1/50
200/50= 4