Let Ravi’s present age be x years.
After fifteen years,Ravi’s age = 4x years.
Fifteen years from now,Ravi’s age = (x+15)years.
According to question, 4x = x+15
⇒4x−x=15 [Transposing x to L.H.S.]
⇒3x=15
⇒3x3=153 [On Dividing both sides by 3]
⇒x=5 years
Hence,Ravi’s present age be 5 years.