Answer:
1/10 liters.
Explanation:
If the scientist had 3/5 Liter of solution and used 1/6 of it, he used (1/6)*(3/5) liters. In order to multilply fractions you have to multiply nominator with nominator and denominator with denominator as follow
Note that you can simplify this results dividing by 3 both nominator and denominator
In conclusion, the scientist used 1/10 liters.