Given data : Distance between Pune to Mumbai (D) = 200 km Speed of A (A) – Speed of B (B) = 20 km/hr Meeting time while travelling towards each other = 2 hours Speed of C (C) = (B + 10) km/hr Formula used : Speed = Distance/time Relative speed A and B (moving towards each other) = (Speed)A + (Speed)B Calculation : Let, speed of B = x km/hr Speed of A=(x+20) km/hr The relative speed of A and B while travelling towards each other = A + B ⇒x+x+20 ⇒(2x+20) km/hr Relative Time to cover distance = Distance/(Relativetime) ⇒2=200/(2x+20) ⇒2×(2x+20)=200 ⇒4x+40=200 ⇒4x=16 0 ⇒x=40 km/hr ⇒ Speed of A=x+20=40+20=60 km/hr ⇒ Speed of B=x=40 km/hr ⇒ Speed of C=B+10 ⇒40+10=50 km/hr Time required for C to travel from Pune to Mumbai = Distance/Speed ⇒200/50=4 hours ∴ C will take 4 hours for travelling from Pune to Mumbai.