## Microsoft Interview Question for Program Managers

• 0

Comment hidden because of low score. Click to expand.
0
of 0 vote

D: distance between 2 trains
v1,v2: speeds of two trains
v3: speed of bird(v3>v1 &&v3>v2)

1)Find the time taken to collide
T1=D/(v1+v2)

2)total distance traveled by the bird
D2=T1*v3

3)# of times bird makes a U turn
Maybe infinite (not sure)

Comment hidden because of low score. Click to expand.
0

You are right and number of turns is infinite.

Comment hidden because of low score. Click to expand.
0
of 0 vote

hey i also think so

Comment hidden because of low score. Click to expand.
0
of 0 vote

trains traveling in opposite directions never collide

Comment hidden because of low score. Click to expand.
1
of 1 vote

You fool, why won't trains travelling in opposite directions not collide according to the given question.
N plz apply common sense before writing "can never collide".

Comment hidden because of low score. Click to expand.
1
of 1 vote

First of all trains will never travel on the same track in opposite directions.

Comment hidden because of low score. Click to expand.
0

Obviously you don't know much about how trains travel in China.

Comment hidden because of low score. Click to expand.
0
of 0 vote

trains traveling in opposite directions never collide

Comment hidden because of low score. Click to expand.
0
of 0 vote

Train travelling in opposite direction may collide, train travelling in same direction may collide.. only one train can also collide with itself.. ask Indian Railway..
what about the poor bird.. its not even afraid of train whistle..it should die before the last three U turns. :)

Comment hidden because of low score. Click to expand.
0
of 0 vote

u all are bastards

Comment hidden because of low score. Click to expand.
0
of 0 vote

zglgjg is right.
No. of u turns is indefinite,the problem can be identified when there is too short a distance between the trains ie when they are about to collide.

Comment hidden because of low score. Click to expand.
0
of 0 vote

what is the answer for the second part i.e number of trips made by bird? there will be a infinite series right ..but what is it?

Comment hidden because of low score. Click to expand.
0
of 0 vote

Everybody know how to find the distance traveled by the bird. The attraction of the question is the second part... The answer will surprise you..... It depends on the size of the bird (If its a point then infinite, if it is not a point then why are we even solving such a puzzle :). BTW for the trains never colliding read: en.wikipedia.org/wiki/Zeno%27s_paradoxes

Comment hidden because of low score. Click to expand.
0
of 0 vote

distance traveled: D/vb, where D is the initial distance and vb is the speed of the bird;

Time U turned: infinite. Suppose finite, at the last U turn, suppose the trains are d apart, in d/(vt + vb) time, the bird run into the other train, however the trains are still d(1 - 2vt/(vt + vb))>0 apart, which means there is another U turn. contradiction

Comment hidden because of low score. Click to expand.
0
of 0 vote

if the time of collision of two trains is finite, how can the number of U turns be infinite??

Comment hidden because of low score. Click to expand.
0

perfect !!! number of U turns never will be infinite.

Comment hidden because of low score. Click to expand.
0
of 0 vote

ok i understand

Comment hidden because of low score. Click to expand.
0
of 0 vote

Trains travelling in opposite direction on the same track towards each other.
Now is that clear U IDIOTS.

Comment hidden because of low score. Click to expand.
0
of 0 vote

I just did this yesturday in class, train 1 goes 40mph, train 2 goes 60mph, the bird starts with the faster train and can fly 90mph, having to turn around when he reaches the other train and vice versa until the 2 trains collide. I got that the bird flew 130miles before they crashed.

Name:

Writing Code? Surround your code with {{{ and }}} to preserve whitespace.

### Books

is a comprehensive book on getting a job at a top tech company, while focuses on dev interviews and does this for PMs.

### Videos

CareerCup's interview videos give you a real-life look at technical interviews. In these unscripted videos, watch how other candidates handle tough questions and how the interviewer thinks about their performance.