Let present age of Arun is = 3X
and present age of Bhargava = 4X
Then 10 year ago Arun was half of Bhargava in age
(3X - 10) =(1/2)(4X-10)
(3X - 10) =( 2X-5)
X = 5
So present age of Arun is = 3X = 3*5 = 15
and Bhargava is = 4X = 4*5 = 20
Sum of their age = 15+20 = 35
ANSWER = 35