MM Chapter 9 Probability

If the probability of Chris scoring 50 or more marks in the exam is 0.7, then the probability he scores less than 50 marks is:

• 0.3

• 0.4

• 0.7

• 0.8

A spinner is coloured red, yellow, blue and green. When spun the probability that it lands on red is 0.1, yellow is 0.2 and blue is 0.4. What is the probability that it lands on green?

• 0.1

• 0.2

• 0.3

• 0.4

Phillip is making a sign, and has cut the letters of the word THEATRETTE out of wood and placed them in his toolbox. If a letter is selected at random from the toolbox, then the probability that it is a T is

Of a group of 25 people in a restaurant, three chose a vegetarian meal, five chose fish, ten chose beef and the rest chose chicken for their main course. What is the probability that a randomly chosen diner chose chicken?

A square has side length of 4 metres. Inside the square is a circle of radius 1.5 metres. If a dart thrown at the square is equally likely to land at any point inside the square, then the probability that it will land outside the circle is closest to:

• 1. 0.442

• 1. 0.295

• 1. 0.558

• 1. 0.250

An experiment consists of tossing a coin and then rolling a fair six-sided die. What is the probability of observing a head and a ‘six’?

If 𝐴 and 𝐵 are events such that Pr(𝐴)=0.35, Pr(𝐴∩𝐵)=0.18 and Pr(𝐵)=0.38, then Pr(𝐴∪𝐵) is equal to

• 1. 0.73

• 1. 0.15

• 1. 0.21

• 1. 0.55

If 𝐴 and 𝐵 are events such that Pr(𝐴)=0.47, Pr(𝐵)=0.28 and 𝐵⊆𝐴, then Pr(𝐴∪𝐵) is equal to

• 1. 0.47

• 1. 0.75

• 1. 0.62

• 1. 0.13

In Imogen’s class 15 students play tennis, 14 play basketball and 7 play both. The probability that a randomly chosen student plays basketball, given that they play tennis, is