Jammu Express is 1.2 km long and is running along the Kerala express at speed of 80km/hr. Kerala express is 2/3rd the length of Jammu express and runs at 60 km/hr. How much time will it take for Jammu express to overtake the Kerala express. 

6 Min

Length of Kerala express = 800 m

Speed = \(\frac{Distance }{Time }\)

According to the question:

(80 - 60) x \(\frac{5 }{18 }\) = \(\frac{\text{1200 + 800}}{Time }\)

20 x \(\frac{5 }{18 }\) =  \(\frac{\text{2000}}{Time }\)

\(\frac{50 }{9 }\) = \(\frac{\text{2000}}{Time }\)

Time = \(\frac{\text{2000 x 9}}{50}\)

Time = 360 seconds or 6 minutes