Apparently probability is supposed to be easy but I'm finding it really confusing.....
Would anyone be able to please answer these questions for me with working? They are out of the 'Maths in Focus' text book from 'Tree Diagrams and Probability Trees' in Exercise 11.5.
7. The probability of a certain type of photocopier needing a service on any one day is 0.3. Find the probability that a school with two of these photocopiers will need to service, on a particular day,
(a) 1 machine
(b) Both machines
(c) neither of them
9. A certain type of plant has a probability of 0.85 of producing a variegated leaf. If I grow three of these plants, find the probability of getting a variegated leaf in
(a) two of the plants
(b) none of the plants
(c) at least one plant
11. A bad contains 3 yellow balls, 4 pink balls and 2 black balls. If 2 balls are chosen at random, find the probability of getting a yellow and a black ball
(a) with replacement
(b) without replacement
There's others I'm stuck on but if I manage to understand these hopefully I can do the other ones. Thanks for you help!
Would anyone be able to please answer these questions for me with working? They are out of the 'Maths in Focus' text book from 'Tree Diagrams and Probability Trees' in Exercise 11.5.
7. The probability of a certain type of photocopier needing a service on any one day is 0.3. Find the probability that a school with two of these photocopiers will need to service, on a particular day,
(a) 1 machine
(b) Both machines
(c) neither of them
9. A certain type of plant has a probability of 0.85 of producing a variegated leaf. If I grow three of these plants, find the probability of getting a variegated leaf in
(a) two of the plants
(b) none of the plants
(c) at least one plant
11. A bad contains 3 yellow balls, 4 pink balls and 2 black balls. If 2 balls are chosen at random, find the probability of getting a yellow and a black ball
(a) with replacement
(b) without replacement
There's others I'm stuck on but if I manage to understand these hopefully I can do the other ones. Thanks for you help!