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 100 years. Can you tell my grandson age in years?
Choose the most appropriate option: A) 50 years B) 20 years C) 5 years D) 10 years E) 90 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 120 years,
g + s + m = 100.
The above system of 3 equations in 3 unknowns (g, s and m) can be solved as follows:
g + 365g / 52 + 12g = 100 or
52g + 365g + 624g = 5,200 or
g = 5,200 / 1,041 = 5 years
Answer : 5 years
<result>C</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 100 years. Can you tell my grandson age in years?