Question : A train can cross a 1200-metre-long bridge completely in 16 seconds. It can cross a 1600-metre-long bridge completely in 20 seconds. What is the speed of the train?
Option 1: 360 km/hr
Option 2: 450 km/hr
Option 3: 540 km/hr
Option 4: 270 km/hr
Correct Answer: 360 km/hr
Solution :
Given,
Length of 1st bridge = 1200 m and time = 16 seconds
Length of 2nd bridge = 1600 m and time = 20 seconds
We know,
Distance = Speed × Time
Length of the 1st bridge = 1200m and time = 16 s
Distance = Length of the train + Length of the bridge
Now, Distance = Speed × Time
⇒ Length of the train + 1200 = Speed × 16
⇔ Length of the train = (16 speed – 1200).............(1)
Now, we have Length of the 2nd bridge = 1600m and time = 20 s
⇒ Distance = Length of the train + Length of the 2nd bridge
⇒ Distance = Length of the train + 1600
⇒ Distance = Speed × 20
⇒ Length of the train + 1600 = 20 $\times$ speed
From (1), we get,
⇒ 16 speed – 1200 + 1600 = 20 $\times$ Speed
⇒ 400 = 4 × speed
⇒ Speed = 100 m/s
⇒ Now, to convert m/s into km/h, we have to multiply the number by $\frac{18}{5}$
⇒ 100 m/s = 100 × $\frac{18}{5}$ = 360 km/hr
Hence, the correct answer is 360 km/hr.
Related Questions
Know More about
Staff Selection Commission Multi Tasking ...
Application | Cutoff | Selection Process | Preparation Tips | Eligibility | Exam Pattern | Admit Card
Get Updates Brochure
Your Staff Selection Commission Multi Tasking Staff Exam brochure has been successfully mailed to your registered email id “”.
Upcoming Exams
Trending Articles around SSC MTS
