beatthegmat.com Probability set #1

[cindyqtran]

question: if you draw a whole number from 1 to 10 at random, what are the odds in favor of getting a 7?
the answer is 1:9

[guest]

Why woudn't it be 1 out of 10? Since there are ten numbers and you are selecting one of them?

[abramson]

I think its because when you consider 'odds' it is usually denoted as 'probability of event occurring: probability of event not occurring'

In this case then, the answer 1:9 would make sense, since there is 1 out of 10 chances of event occurring, and 9 out of 10 chances of it not occurring.

Can anyone confirm that I am not wrong with this logic?

Thanks!

[JadranLee]

abramson, you are 100% correct.

By the way, I've never encountered a real GMAT question that uses the word "odds". All the questions I have seen deal with probability rather than odds. The probability of choosing a 7 in this example is 1/10.

-Jad