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?

So you're 120 in years so your grandson is 120 months, there's 12 months in a year. so times that by 10 - he's 10 years old. How many weeks are there in 10 years? 52 weeks in 1 year so times by 10 again and theres 520. So your grandson is 520 days old, 365 days in a year. 520 - 365 is 155. So he's 1 year and 155 days. The average month has 30.4 days per month (365.25/12) So 155 days would be 5.1 months or 5 months and 3 days.

So the final answer is 1 year, 5 months and 3 days.

G = grandson's age

s = son's age

m = my age

"grandson is about as many days as my son is in weeks"

s = 7g

"my grandson is about as many weeks as i am in years"

m = 12g

"my grandon, my son and i together are 120 years old"

g + s + m = 120

g + (7g) + (12g) = 120

20g = 120

g = 6

s = 7g = 7 (6) = 42

m = 12g = 12 (6) = 72

My age in years is 72