Final answer:
Imogen practiced her scales for 1/6 of an hour.
This correct answer is B.
Step-by-step explanation:
To find the fraction of an hour that Imogen practiced her scales, we need to multiply the fraction of an hour she practiced in total by the fraction of that time that she spent practicing her scales.
Imogen practiced for 1/4 of an hour, and she practiced her scales for 2/3 of that time.
Multiplying these fractions, we get (1/4) * (2/3) = 2/12 = 1/6. Therefore, Imogen practiced her scales for 1/6 of an hour.
This correct answer is B.