Question

Question 3

(a) Discuss probability, independence and mutual exclusivity, giving examples to illustrate your answer. (6)
(b) i. How many ways are there of choosing a committee of three people from a club of ten? (2)
ii. How many ways are there of selecting from those three people a president, secretary and treasurer? (2)
iii. Illustrate your answer to the second part of the question with a tree diagram. (2)

Question 4
An ice-cream vendor on the beachfront knows from long experience that the average rate of ice-cream sales is 12 per hour. If, with two hours to go at work, she finds herself with only five ice-creams in stock, what are the probabilities that
(a) she runs out before the end of the day; (4)
(b) she sells exactly what she has in stock by the end of the day without any excess demand after she sells the last one; and (3)
(c) she doesn't sell any?

Answer 1

Dear student, please post question one at a time.

a)  Probability is the measure of the likelihood that an event will occur. It is expressed as a number between 1 and 0. An event with a probability of 1 can be considered a certainty.

When two events are said to be independent of each other, what this means is that the probability that one event occurs in no way affects the probability of the other event occurring. An example of two independent events is as follows; say you rolled a die and flipped a coin.

Two events are mutually exclusive or disjoint if they cannot both occur at the same time. A clear example is the set of outcomes of a single coin toss, which can result in either heads or tails, but not both.

b) i) Total number of ways of choosing a committee of three people from a club of 10 to choose three people from 10 is

ii) Total number of ways `there are of selecting from those three people a president, secretary, and treasurer is

iii)

c)