1/2 of Sammie's age is equal to 1/5 of Tommy's age. If their total age is 84 years, how old is Tommy?

Answer 1

(1/2)s = (1/5)t, where s is Sammie's age, and t is Tommy's age
s = (2/5)t

s + t = 84
(2/5)t + t = 84
times 5
2t + 5t = 420
...
t = .....