Five years ago, Nuri was thrice as old as Sonu. After ten years from now, Nuri will be twice as old as Sonu. Present ages of Nuri and Sonu respectively are

50 years, 20 years

Assume Nuri's present age =n

Assume Sonu's present age =s

n-5 = 3*(s-5)

n = 3s-10

Also, (n+10) = 2(s+10)

So, 3s-10+10 = 2s+20

s = 20

n = 50

The correct answer is option (4) : 50 years, 20 years