SOLUTION: Roel is as old as the combined age of his two brothers Oski and John. But John is two years older than Oski. The combined age of the three last year was 3/4 of their combined age a

The combined age of three persons increases by 3 years in one year, which is totally obvious.


Hence, if their combined age last year was 3/4 of their combined age this years,

it means that 1/4 of their combined age this year is 3 years.


It, further, implies that their combined age this year is 12 years.


Next, the problem says that Roel is as old as the combined age of his two brothers.

Hence, Roel age is 6 years, which is half of 12 years and is exactly the sum of ages of the two other brothers.


One more step further.  The two younger brothers combined age is 6 and John is two years older than Oski.


It gives you the 


    ANSWER.  Roel is 6 years old;  John is 4 years old and Oski is 2 years old.


Good problem for the preschool students.