# Shortcut of Trains-2

Shortcut 55:
Train crossing a man on another train in same direction
$T=\frac{L_T}{S_1\sim S_2}$
Question:
Two trains A and B of length 100m and 200 are travelling at a speed of 72kmph and 54kmph respectively in same directions. How long will train A take to cross a man travelling in train B?
LT = 100, (Length of train crossing the man)
S1 = 72kmph = 72(5/18)mps = 20mps
S2 = speed of the man travelling in train B
S2 = 54kmph = 36(5/18)mps = 10mps
Substitute the values in the above formula, we get
T = (100)/(20-10)
= 10 seconds

Shortcut 56:
Time taken to meet from different stations
$T=\frac D{S_1+S_2}$
Question:
Two trains A and B start from stations 1 and 2, 300km apart at 9am and travel towards each other at a speed of 30kmph and 50kmph respectively. At what time they will meet?
D = 300km
S1 = 30kmph; S2 = 50kmph
T = 300/(30+50)
= 3.75 hours
= 3 hours 45 minutes
The time at which the two trains will meet is,
= 9am + 3:45 hours
= 12:45pm

Shortcut 57:
Time taken for trains to meet in same direction
$T=\frac D{S_1\sim S_2}$
Train A starts from station at 10am at a speed of 50kmph. Train B starts from the same station at 11am at a speed of 55kmph. How long will train B take to meet train A?
Difference in time of starting between the two trains = 11am – 10am = 1 hour
Distance travelled by train A in 1 hour = 1 x 50
= 50km
D = 50, distance between two trains
S1 = 50; S2 = 55
T = 50/(55 – 50) = 10 hours
The two trains will meet at 11am + 10 hours
= 9pm

Shortcut 58:
Speed ratio
$S_1:S_2=\sqrt a:\sqrt b$
a, b – time taken by respective trains travelling in opposite direction, to reach destination after they meet.
Question:
Two trains start from stations A and B. Speed of train from A is 60kmph. The two trains meet each other and take 9 and 4 hours to reach the destined stations. What is the speed of train from B?
a = 9 hours
b = 4 hours
S1 = 60kmph
S1 : S2=√9 : √4
60 : S2 = 3 : 2
S2 = 40 kmph

Show full profile

#### sivaCustomer

X
- or -
Register New Account
##### Compare items
• Total (0)
0
ARE YOU READY? GET IT NOW!
Increase more than 500% of Email Subscribers!
Your Information will never be shared with any third party.
ARE YOU READY? GET IT NOW!
Get Weekly Current Affairs Magazine to your inbox.
Your Information will never be shared with any third party.
CURRENT AFFAIRS THAT MATTERS TO YOU
Get Weekly Current Affairs Magazine to your inbox.