## Thinking Mathematically (6th Edition)

age of Charles Coburn(Uncle)is $60$ and age of woman is $20$.
Let $x$ be the current age of Charles Coburn(Uncle). Let $y$ be the current age of woman. $x=3y$ …… (1) When Uncle replies “Ah, but in 20 years’ time I shall only be twice be her age. It means: $x+20=2\left( y+20 \right)$ ...... (2) Now In equation (2)put value of $x$ from equation(1): \begin{align} & 3y+20=2\left( y+20 \right) \\ & 3y+20=2y+40 \\ & y=20 \end{align} Put $y=20$in equation (1); \begin{align} & x=3\left( 20 \right) \\ & x=60 \\ \end{align} So, age of Charles Coburn(Uncle)is $60$ and age of woman is $20$. Hence, age of Charles Coburn(Uncle)is $60$ and age of woman is $20$.