Once you attempt the question then PrepInsta explanation will be displayed.
let Deepak’s age be x
If Deepak’s age is x, then Dipti’s age will be 3x.
Rani is 4 years younger than Dipti, so her age will be 3x-4
Given, x+3x+3x-4 = 66
7x = 70
x = 10
Therefore, Dipti’s age will be 3*10 = 30 years