Sue is 5 years older than her younger brother,Andy.Andy is 3 years older than Tom.Tom is the you

Sue is 5 years older than her younger brother,Andy.Andy is 3 years older than Tom.Tom is the you
gest one in the family.If the sum（总数） of the three children‘s ages is 17,how old is the eldest（年纪最大的） child?
对不起，应该是Tom is the youngest one in family。