Five years ago, Tom was one third as old as his father was then.In 5 years, Tom will be half as old as his father will be then. Find their ages now.
\(\text{t is Tom, f is father}\\ (t-5)=\dfrac{f}{3}\\ (t+5)=\dfrac f 2\\ \text{add these}\\ 2t = \dfrac 5 6 f\\ t = \dfrac{5}{12}f\\ \dfrac{5}{12}f - 5 = \dfrac f 3\\ \dfrac{f}{12}=5\\ f = 60,~t=25\)
