Mr Sommer's total time = 50 minutes.
Time he spent, reviewing the homework = 10 minutes.
Fraction of the time he reviewed the homework = [tex]\frac{10}{50}=0.2[/tex]
Mr Young's total time = 60 minutes.
Time he spent reviewing = 12 minutes
Fraction of the time he reviewed the homework =[tex]\frac{12}{60}=0.2[/tex]
Both the teachers spent the same fraction of time reviewing the homework.