The difference between the ages of two of my three grandchildren is 3. My…

Explanation

Let the age of youngest grandchildren be x, then eldest = 3x.

Now according to question

3x = y + x + 2

=> y = 2x -2

so ages of all the 3 grandchildrens are 3x , 2x-2 and x respectively.

also difference between two of the child’s ages is 3

so 2x-2 -x = 3=>

x = 5

This is the ages of youngest grandchild

Now the age of eldest grandchild will be

3x = 15