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 150 years. Can you tell my son age in years? Pick one:
A) 63 years  B) 60 years  C) 50 years  D) 53 years  E) 46 years
Let m be my age in years. If s is my son's age in years, then my son is 52s weeks old. If g is my grandson's age in years, then my grandson is 365g days old. Thus,
365g = 52s.
Since my grandson is 12g months old,
12g = m.
Since my grandson, my son and I together are 150 years,
g + s + m = 100.
The above system of 3 equations in 3 unknowns (g, s and m) can be solved as follows:
52s / 365 + s + 12 x (52s / 365) = 150 or
52s + 365s + 365 x (624s / 365) = 365 x 150 or
s = 54,750 / 1,041 = 53 years
Answer = 53 years
<result>D</result>
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 150 years. Can you tell my son age in years?