IBM Technical Paper 2 - Interview Preparation MCQ

Flop is a unit of? 

#define hello(x,y) printf(#expr"%d",expr);

main(){

float x=1,y=2;

expr=x/y;

hello(expr);

}

A question on set theory.it was given that less than 30 persons in class.

4 cows are there at the four corners of a square. if the radius of the rope is 1 and length of one side of the square is 14, find the area along the square which the cow cannot gaze.

A belongs to the truther tribe  who says yes. B belongs to the liters tribe who says no always. when A&B were asked to which group do they belonged to both of them replied yes.when a third person C was asked whether A&B belong to same group, he notified groups he answered No. to which group do A,B and C belong? 

There were three clocks they gave alarm after 24 secs, 12 secs and 36 secs. if they rang simultaneously at 8:20, then at what time they again rang simultaneously? (something like this but numbers may differ). 

A plane starts from a place A , it goes 1000 kms south then 1000 km east then 1000 km north and 1000 km west, what is it distance from the starting place?