Xiao Ming's grandfather is 60 years old. His father's age is 7 / 12 of his grandfather's. Xiao Ming's age this year is 2 / 7 of his father's. how old is Xiao Ming this year? Determinant
10 years old
(60*7/12)*2/7=10
10 years old
(60*7/12)*2/7=10