Question

The grandfather years=grandson's month
The grandson's days=father's week
Total age of father,grandfather and grandson is 140 years

Answer 1

For better calculation, considering all months is of 30 days , 
1 year = 360 days
Let Grandfather age be D days 
Father age be B days 
Grandson age be P days
A/q,
D + B +P = 140 ×360 days
now, Grandfather age in year = Grandson age in months
so, D = 12 P
now, Father age in week = Grandson age in days
so, B = 7 P
now , from first equation,
D + B +P = 140 ×360 days
⇒12P + 7P +P = 140× 360
⇒20 P = 140 ×360
⇒P = 2520 days 
       = 2520/360 = 7 years
so, B = 7×P = 7×7 = 49 years
and , D = 12 P = 12× 7 = 84 years 
so, Grandson = 7 years
      Father = 49 years
      Grandfather = 84 years

Hope this will help you :)