m - Marty's age
w - Warren's age
Marty is 3 years younger than 6 times his friend Warren's age.
6 times his friend Warren's age ----- 6w
Marty is 3 years younger than 6 times his friend Warren's age.
(1) m = 6w - 3
(2) m + w > 11
Substitute (1) into (2).
6w - 3 + w > 11
7w > 14
w > 2
Warren can be as young as 3 years old.
