Lottery probability

1. Apr 21, 2012

bartowski

thanks for helping :)

Last edited: Apr 21, 2012
2. Apr 21, 2012

Think about this as follows: how many ways are there to choose 2 numbers from 18? (no replacement, order doesn't matter)

3. Apr 21, 2012

bartowski

numerator: 18C2, 18C2, 19C2 --- but i'm not sure if you ADD or MULTIPLY these
denominator: 55C6

4. Apr 21, 2012

Dickfore

$$\frac{C^{2}_{18} \, C^{2}_{18} \, C^{2}_{19}}{C^{6}_{55}}$$

Wolfram Alpha

This looks terribly high?!

5. Apr 21, 2012

bartowski

i was thinking of that.
if you add it on the other hand, its too low

i'm not quite sure with my solution
:(

Last edited: Apr 21, 2012
6. Apr 21, 2012

Dickfore

No, but this not a probability ot win! This is just a fraction of the total number of outcomes that satisfy your condition. It doesn't mean that if you fill A ticket satisfying this condition that you have this probability to win.

7. Apr 21, 2012

bartowski

so you think the solution is right? :)

8. Apr 21, 2012

Dickfore

Yes. The solution is correct.

9. Apr 21, 2012

bartowski

thanks! :)

10. Apr 21, 2012