Time taken by two trains running in opposite directions to cross a man

1.	Time taken by two trains running in opposite directions to cross a man standing near a pole is 48 seconds and 38 seconds respectively and it took 42 seconds for the trains to cross each other. What is the ratio of the speed of the trains?1. 3 : 22. 2 : 33. 4 : 14. 8 : 1
Answer» Correct Answer - Option 2 : 2 : 3 Given: Both trains running in the opposite direction Both trains cross the man in 48 seconds and 38 seconds Formula used: Speed= distance/time Relative speed = when train in opposite direction = (x+y) m/s Calculation: Let the speed of trains be x m/s and y m/s respectively Length of the first train = speed × time = 48x Length of the second train = speed × time = 38y \(\frac{{48x + 38y}}{{x + y}} = 42\) ⇒\(48x + 38y = 42x + 42y\) ⇒ \(6x = 4y\) ⇒\(\frac{x}{y} = \frac{2}{3}\) ∴ The ratio of the speed of the trains is 2 : 3

Time taken by two trains running in opposite directions to cross a man standing near a pole is 48 seconds and 38 seconds respectively and it took 42 seconds for the trains to cross each other. What is the ratio of the speed of the trains?1. 3 : 22. 2 : 33. 4 : 14. 8 : 1

Answer» Correct Answer - Option 2 : 2 : 3

Given:

Both trains running in the opposite direction

Both trains cross the man in 48 seconds and 38 seconds

Formula used:

Speed= distance/time

Relative speed = when train in opposite direction = (x+y) m/s

Calculation:

Let the speed of trains be x m/s and y m/s respectively

Length of the first train = speed × time = 48x

Length of the second train = speed × time = 38y

\(\frac{{48x + 38y}}{{x + y}} = 42\)

⇒\(48x + 38y = 42x + 42y\)

⇒ \(6x = 4y\)

⇒\(\frac{x}{y} = \frac{2}{3}\)

∴ The ratio of the speed of the trains is 2 : 3

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