To solve this problem you first need to establish what it is you are looking for.. if you knew the grandson age then you could find your son and you. So that is what we need to find and since we don't know it, we will call it x.
Grandson = x Son = 7x You = 12x
Then it says the sum of the 3 is 100.... x + 7x + 12x = 100 then solve and find that x = 5. So to determine your age, just put 5 in for x and you get 60... dang your old ha
We have to find the common multiple for each object. And we know that we have 39 penciles and 26 pens. The common multiple for both would be 13. 39/13 = 3 and 26/13 = 2 From there we learn that each student would get 3 penciles and 2 pens
