300 students participated in a symposium with 3 conferences in sequence.

Half of the students that attended the first conference, attended neither the other two.

One-third of the students that attended the second conference, attended neither the other two.

And one-fourth of the students that attended the third conference, attended neither the other two.

Knowing that the three conferences were attended by the same number of students, and that each of the 300 students attended at least one conference :

a) how many students attended each conference ?
b) how many students attended only one conference ?
c) how many students attended only two conferences ?
d) how many students attended all 3 conferences ?

One unique solution !

(In reply to re(2): Answer by Timothy Bard)

It's too late now, but I should stated : "No computers".

Nothing against computers (in fact, all my professional life, I worked with them), but I expected a little bit more of thinking, not trial and error, not brute force.

This problem can be solved by hand, just pencil and paper. But, as I said before, it's too late now.

But, if anyone wanna try to solve it by hand, be my guess !!!

And this is the real challenge !!!!

Posted by pcbouhid on 2005-05-11 23:03:05