Question

i am as many days as my dad in weeks, as many months as my grandpa in years. together the three of us are 120. what is my age, my dads age and my grandpas age?

Answer 1

120 what? Do we assume units of years for this number?

Answer 2

yes 120 years

Answer 3

Can start with A+B+C=120 to represent the three ages in years, then make equations to relate A and B using number of days in a year, and A and C using number of weeks in a year.
Will probably have to round off some values along the way since there isn't an exact whole number of days or weeks in a year.

Answer 4

Example: A's age in days is 365.35A, B's age in weeks is 52.18B, etc.

Answer 5

would you set it up like 365.35A+52.18B+C=120?

Answer 6

No, because the units on the numbers would no longer match.
You need to do it a little at a time. For simplicity, let's ignore leap years and take 1 year = 52 weeks = 365 days.
A's age in days equals B's age in weeks, so 365A = 52B.
A's age in months equals C's age in years, so 12A = C.
Then you can do some substitutions until you have one equation with one variable.