Technical - Java

  Puzzle

1. U r a land scape designer and your boss asked u to desing a landscape such that you should place 4 trees equidistance from each other. (Distance from each tree to the other must be same) I couldnt answer there but after coming out of the interview room, I  could get the answer. It is u should place them in the shape of 
triangular pyramid.

2. The second ques was like this. in a race u drove 1st lap with 40kmph and in the second lap at what speep u must drive so that ur average speed m ust be 80kmph. Sorry guys, i dont know this but I know ans is not simple avg.
Some other interview ques: 

Q. you have to draw 3 concentric circles with a line passing thru  their center without lifting hand. 
A. Its simple. just start the line complete one circle move inside circles along the line and then draw second circle. like wise rest.

Q. You entered a room. You have only watch with you. When u entered the room a bulb is touching your head. You must find the height of the room.

A. drop it from the room and find the time at which it strikes the floor. using formula
physics formula s = (at^2)/2

Q. A rectanglar paper is there. At a corner a rectangular size paper is taken from it. now you have to cut the remaining paper into two equal halves.
A. Its easy guys. just try it on th e paper. You must fold the part which has complete paper and select half of it and then fold the part which cut and select half of it and then cut along the foldings.