Math problem puzzle My grandson is about as many days as my son in weeks, and my grandson is as many months as I am in years. My grandson, my son and I together are 120 years. Can you tell me my age in years ? It's really simple : The above system of 3 equations in 3 unknowns can be solved as follows. I know the solution should i write it ?

Assuming $x, y,\text{ and } z$ are the ages of your grandson, your son, and you respectively, expressed in years, then your system is:

$$365x = 52y$$ $$12x=z$$ $$x+y+z=120$$

Therefore $x=6$, $y=42$ and $z=72$