Question

172. A goods train crosses 2 km long bridge in
3 min. If length of the train is half of the bridge,
then find the speed of the train:
a. 45 km/hr.
b. 40 km/hr.
c. 80 km/hr.
d. 60 km/hr.​

Answer 1

Answer:

60 km/ hr

Step-by-step explanation:

length of the bridge = 2 km

time taken to cross the bridge = 3 min

3 min = 3 /60 = 1 / 20 hrs

length of the train = half of the bridge

= 1 km

To cross the bridge of length 2 km by 1 km long train

total distance traveled by the train = length of the bridge + length of the train itself

total distance traveled = 2 + 1 = 3 km

speed = total distance ÷ time

speed = 3 km ÷ 1/20 hr

= 3 × 20

= 60 km/hr

Answer 2

Answer:

60

Step-by-step explanation:

3/60=1/20

2+1=3

1/20÷3=60