This was my doubt a while ago
I solved it today and it matched. But then I flipped through my previous try and I don't understand why it was wrong.
What I had done was
The numbers chosen have atleast 1 multiple of 3
So out of the 100 numbers In the sample space 33 are multiples of 3.
So chosing 1 number out of this is 33c1
And the second number can be anything
So probability is 33c1*99c1/100c2
Why is this wrong?