Tell Me The Age

The terminology is a bit confusing as you call grandfather and father by the same term, father.

But, to start:
G = grandfather
F = father
S = son
1 yr = 365.25 days = 52 weeks

G + F + S = 100
If Father (for example), is 1560 weeks old (30 yrs old), then son is 1560 days old, or about 4 yrs old. If grandfather is 50 yrs old, then son is 50 months old, or a little over 4.

So the numbers must be higher but we're on the right track. The current total is about 84 so we need to bring things up by 16 years. The closest I can get without getting too deeply into fractions is:

Grandpa is 60, Father is 35 and son (the grandson) is 5.

you tried this over and over intill you found the right answer?

Easier way:

G+F+S=100
F=7S (days to a week)
G=12S (months to a year)
12S+7S+S=100
20S=100
S=5

Tell Me The Age
Dear Jespah,
Although your answer is correct but the reasoning logic is incorrect
here is the answer:
Let f, s and g be the ages in years, of the father, son and grandson, respectively.
As I know that you're all going to get technical on me, I'll use 6 d.p. for my calculations.
In a year there are technically 365.242199 days.
This leaves us with 52.177457 weeks.
Months are fixed at 12.
(note: this also works if you use 365 and (365/7) for days and weeks, respectively.)

Age of the son in weeks is the same as the age of the grandson in days:
52.177457*s = 365.242199*g

Age of the grandson in months is the same as the age of the father:
12g = f

Sum of their ages is 100 years:
f + s + g = 100

Solving these, we get:
s = (365.242199/52.177457)*g
= 7g
and
f = 12g

Therefore:
12g + 7g + g = 100
20g = 100
g = 5

s = 7g
s = 35

f = 12g
f = 60

The father is 60 years old, the son is 35 years old and the grandson is 5 years old.

dear mathur

You made a very long journey and it was way easier.

Dear fbaezer

Thanks for the suggestion but I think short cuts can be sometimes confusing.So its always good to make people understand the way I did