Question Number 65951 by ketto2 last updated on 06/Aug/19
![](https://www.tinkutara.com/question/8913.png)
Commented by Tony Lin last updated on 06/Aug/19
![if the son is x now ⇒his father is 30+x after 10 years ⇒40+x=3(x+10) ⇒x=5 so the son is 5 years old and his father is 35 now](https://www.tinkutara.com/question/Q65956.png)
$${if}\:{the}\:{son}\:{is}\:{x}\:{now}\: \\ $$$$\Rightarrow{his}\:{father}\:{is}\:\mathrm{30}+{x} \\ $$$${after}\:\mathrm{10}\:{years} \\ $$$$\Rightarrow\mathrm{40}+{x}=\mathrm{3}\left({x}+\mathrm{10}\right) \\ $$$$\Rightarrow{x}=\mathrm{5} \\ $$$${so}\:{the}\:{son}\:{is}\:\mathrm{5}\:{years}\:{old} \\ $$$${and}\:{his}\:{father}\:{is}\:\mathrm{35}\:{now} \\ $$