Question

a jar contains five black buttons and six brown buttons. If 8 buttons are picked at random,what is the probability that at least 4 of them are black?

Answer 1

First, we write out the probability formula:

`Pr(E)=\frac{n(R\text{equired outcome)}}{n(Total\text{ outcome) }}`

Total number of tickets = 13

Pr(both Ashley and Matt win) = Pr(Ashley wins) x Pr(Matt wins)

`\begin{gathered} Pr(\text{Ashley win ) }=\text{ }(1)/(13) \\ Pr(\text{Matt win) = }(1)/(13) \end{gathered}`
`Pr(\text{both wins ) }=(1)/(13)*(1)/(13)=(1)/(169)`

The final answer is 1/169

In order to express our answer as a percentage, we multiply by a 100%

= 1/169 x 100% = 0.592% ( to 3 significant figures)