Thread: Last question for the day...

1. Last question for the day...

You have a chance to win a prize by picking 5 numbers from 42, (no repeat) what is your chance to win if:

a. order is important
b. order is not important

2. Originally Posted by SMS386904
You have a chance to win a prize by picking 5 numbers from 42, (no repeat) what is your chance to win if:

a. order is important
b. order is not important
Assuming the numbers are not replaced after each draw:

a. $(\frac{5}{42}) (\frac{4}{41}) (\frac{3}{40}) (\frac{2}{39}) (\frac{1}{38}) = \frac{5!}{(42)(41)(40)(39)(38)}$

b. $^nC_r = \frac{n!}{(n-r)!r!}$ where n = 42 and r = 5

= $\frac{42!}{(42-5)!5!}$