In a box of 20 donuts there are four with cinnamon apple fil

In a box of 20 donuts, there are four with cinnamon apple filling. What is the probability of choosing four donuts, one or more of which have cinnamon apple filling?

Solution

4 ARE CHOOSEN

20 ARE TOTAL

4 ARE CINNAMON

20-4 = 16

PROBABILITY OF BEING CINNAMON = 4/20= 1/5 = 0.2

PROBABILITY THAT OUT OF 4 ONE OR MORE WILL BE CINNAMON = 1 - PROBABILITY NONE IS CINNAMON

PROBABILITY NONE IS CINNAMON = 4C0*(0.25)^0*(0.75)^4 = 0.316

SO PROBABILITY OF BEING ONE OR MORE CINNAMON = 1- 0.316 = 0.6835