Question 682569
Let Peter's age be x years

Arasoo's age = x+4

ali's age x-2 years

Their sum = 47 years

x+x+4+x-2=47
3x=45
x=15

Peter's age = 15
Arasoo's age = x+4 , =19 years

Ali's age = x-2 . = 13 years