Anonymous
Anonymous asked:
Number "a" chosen from set {1,2,3,4,5,6}. Number "b" is chosen from the remaining five numbers. What is the probability that "a/b" is an integer?The best way to screw this one up is to try to come up with a fancy shortcut. Just list all the possibilities. It REALLY doesn’t take that long:
1/2
1/3
1/4
1/5
1/6
2/1
2/3
2/4
2/5
2/6
3/1
3/2
3/4
3/5
3/6
4/1
4/2
4/3
4/5
4/6
5/1
5/2
5/3
5/4
5/6
6/1
6/2
6/3
6/4
6/5
That’s 30 possible a/b outcomes. The bolded ones resolve to integers. There are 8 of them. So the probability you seek is 8/30, or 4/15.
