Lesson: Introduction to Probability

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is the solution to the last problem done like this?
1/5 (is the chance that he will be selected first) ,
4/5 x 1/4 = 4/20 = 1/5 (is the chance that he will be selected second) ...
1/5 + 1/5 = 2/5 = 4/10 = 0.4
gmat-admin's picture

That's a perfect approach. Since this video is an introduction to probability, we don't get into any techniques yet, other than to explain what probability is all about.

Brent, I've got a hard probability question, and I can't seem to figure out how to tackle it. Would you be so kind to take a look?

"If an integer 'n' is to be chosen at random from the integers 1 to 96, inclusive, what is the probability that n(n+1)(n+2) will be divisible by 8?"

A: 1/4
B: 3/8
C: 1/2
D: 5/8
E: 3/4

gmat-admin's picture

This question has been discussed many times on the GMAT discussions forums.

You'll find 4 or 5 diverse solutions from experts here: http://www.beatthegmat.com/if-an-integer-n-is-to-be-chosen-at-random-fro...

Thanks brent, much appreciated!

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