B

Since both trains are moving in opposite direction so their speed must be added.
As we know, speed = [latex] \frac {distance}{time} [/latex]
Time taken by man sitting in second train to pass the first train = [latex] \frac {200}{(60 + 100) \times \frac {5}{18}} [/latex] = 4.5 sec

A

Total floors between Andy & Bimal = 45 - 10 = 35 floor
Relative speed = 34 + 36 = 70 floor/min
Time taken by them to meet = [latex] \frac {Total floors}{Relative Speed} = \frac {35}{70} = \frac {1}{2}[/latex] min
Andy travels in [latex] \frac {1}{2}[/latex] min = [latex] \frac {1}{2} \times 34 = 17[/latex]floors
Floor at which Andy & Bimal will meet = 10 + 17 = 27

B

Distance is same. Then,
[latex]\frac {{s}_{2}}{{s}_{1}} = \frac {{t}_{1}}{{t}_{2}}[/latex]
[latex]\frac {7}{11} = \frac {{t}_{1}}{33}[/latex]
[latex]\Rightarrow {t}_{1} = 21 hour[/latex]
Total time saved = 33 - 21 = 12 hours

A

Since both are moving in same direction so their speed must be subtracted
As we know, speed = [latex]\frac {distance}{time}[/latex]
Length of yrain = (50 - 32) [latex] \times \frac {5}{18} \times 80[/latex] = 400 m

B

Let the distance of winning post from starting point of A be x m
i.e, Distance travelled by A = x m
Distance travelled by B = x - 80 m
And
Speed of A = 3[latex]\frac {2}{3}[/latex] speed of B
[latex]\frac {Speed of A}{Speed of B} = \frac {11}{3}[/latex]
Time is same for Both A& B
i.e, [latex]\frac {x}{x - 80} = \frac {11}{3}[/latex]
3x - 11x = - 880
- 8x = - 880
8x = 880
x = 110