Question

A wheel contains eight slices, numbered sequentially 1 through 8 The probability of landing on each slice is equal. The wheel is spun two times. What is the probability that the sum of the two spins is greater than 10?

Answer 1

There are `64` possible outcomes, from `1+1to8+8`

Explanation:

The favourable ones are the ones that add up to `>=11`

These are:
`38,47,48,56,57,58,65,66,67,68,74,75,76,77,78,83,84,85,86,87,88` for a total of `21`
(if you put this in a matrix with first spin as columns and second spin as rows it will be easier to see and count)

`->P(>10)=P(>=11)=21/64` or just under a third.

Or:
For a first spin of `1or2` there is no possible favourable outcome.
First spin `3->1` possible favourable outcome `(3+8`)
First spin `4->2`, first spin `5->3`, etc.
Then add `1+2+3+4+5+6=21`