Question

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

Answer 1

You need to keep everything in the same units, since the answer is in years, we will let each variable be in terms of years...

Let
G=grandson age in years
S=Son age in years
I = Self age in years

Answer 2

Then, translate each given sentence into an equation..

My grandson is about as many days as my son in weeks,
remember the variables are in years...
days of granson 365*G is same as Son weeks 52*S
365*G = 52*S


grandson is as many months as I am in years
12*G = I


My grandson, my son and I together are 120 years.
G + S + I = 120

Answer 3

you can solve those 3 equations as a system and get values for ages in years,

365*G = 52*S
12*G = I
G + S + I = 120
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if you want a decimal approximation --
S=42.07 yrs , G=5.99 yrs, I=71.93 yrs