Probability Recap

Question 1

1 is/isn’t prime?

Answer 1

Isn’t as it needs to be able to be divided by 2 values(1 and itself) and it can only be divided by 1 value, 1

Question 2

What is the only even prime number?

Answer 2

2

Question 3

0 is/isn’t even

Answer 3

is

Question 4

Two dice are rolled and the ‘score’ is the difference between the numbers shown.

a) What is the probability of getting a score of 3?
b) What is the probability of the score being an odd number?

Answer 4

(Use square for answers)

a) 6/36
b) 18/36

Question 5

Gold example:

Kate takes fruit and a drink to work each day. The probability that she takes an apple is 0.6. The probability that she takes orange juice is 0.45.

What is the probability that she takes

a) an apple and orange juice
b) an apple but not orange juice

Answer 5

a) 0.6 x 0.45 = 0.27

b) p(o) = 0.45
p(o’) = 0.55
0.6 x 0.55 = 0.33

0.55 is the probability of no orange