Question 817284
A grandfather has lived as many years as his grandson has lived months.
 His son has lived as many weeks as his grandson has lived days.
 If you added their ages, you would get 120 years. How old is the grandfather?
:
let x = grandfather's age
let y = son's age
let z = grandson's age
:
"A grandfather has lived as many years as his grandson has lived months."
x = 12z
:
"His son has lived as many weeks as his grandson has lived days."
52y = 365z
y = {{{365/52}}}z
y ~ 7z
:
"If you added their ages, you would get 120 years."
x + y + z = 120
replace x with 12z; replace y with 7z
12z + 7z + z = 120
20z = 120
z = 120/20
z = 6 yrs is grandson's age
the
12(6) = 72 yrs is grandfathers age
and
7(6) = 42 yrs is son's age



 How old is the grandfather?  72