Here is the question:

And here is the answer:

I understand till "There are 20 ways" but then, P(event does not occur), where did the (1/6)^3 come from??

Please help as fast as possible! Thank you.

Guest May 10, 2022

#2**+1 **

It is more confusing becasue some of what is written is WRONG.

There are 20 ways that this can happen

and there are 6*6*6 = 216 different possible rolls

6 choices for the 1st roll, 6 for the second, 6 for the third = 6*6*6 different outcomes (order definitely counts)

**P(that it WILL happen ) =** \(\frac{20}{216}\)

**P( that it DOES NOT happen ) = ** \(1-\frac{20}{216}\)

**P( that it WILL NOT happen twice in a row ) = \((1-\frac{20}{216})^2\)**

Does that make more sense?

Melody May 11, 2022