A train of length 150 meters takes 40.5 seconds to cross a tunnel of length 300 meters. What is the speed of the train in km/hr ?

A.  13 33   
B.  26.67
C.  40   
D.  66.67
Answer: C

Explanation:

speed    =(150 + 300 / 40.5)m/sec
             =(450/40.5x18/ 5) km/hr
            = 40 km/hr