Page 156 - Mathematics Coursebook

16.2 Equally likely outcomes

5 What is wrong with Anders’ argument?

A football team can win, lose or draw a match.
These are the only three possible outcomes and
winning is one of those outcomes.
1
The probability that the team will win is .
3

6 In a game of snooker there are 15 red balls and seven other balls coloured yellow, green, brown, blue,
pink, black and white. Gianni takes one ball at random.

What is the probability that the ball Gianni takes is:
a red b not red c yellow d red, white or blue e orange?

7 A ten-sided dice has the numbers from 1 to 10 on its faces.

Jiao rolls the dice once.
Find the probability of each of these outcomes. Write your answers as percentages.
a 3 b more than 3 c a multiple of 3
d a factor of 12 e more than 12 f less than 12

8 A teacher has 12 red pens, 8 blue pens, 5 black pens and 7 green pens.
She hands one, at random, to each student in the class.

a Find the probability that the first student is given a red pen.
b Deshi wants to have a red pen. By the time the teacher gets to Deshi she has given out two pens
of each colour. Has Deshi’s chance of getting a red pen increased or decreased? Give a reason for
your answer.

16 Probability 155