Maths Connect 2b - Diagrams And Tables - Probability Worksheet
ADVERTISEMENT
1
2
3
4
5
6
7
8
9
10
11
12Key words
3.1
Probability
event
outcome
Find the probabilities of events
Understand that if the probability of an event happening is p, the probability of it not
happening is 1
p
An
event
, such as rolling a dice, can have different
outcomes
.
When a fair six-sided dice is thrown, the possible outcomes are 1, 2, 3, 4, 5 and 6. Each
1
outcome is equally likely. The probability of throwing a 2 is
, as there is a 1 in 6 chance
6
of this happening.
It is certain that one of the numbers 1 to 6 will be thrown. If an outcome is certain, it
1
has a probability of 1. So, if the probability of throwing a 2 is
, the probability of
6
1
throwing a number other than 2 is 1
. We write this as:
6
1
P(2)
6
1
5
P(not 2)
1
6
6
Example 1
A bag contains discs numbered from 1 to 10. One disc is chosen at random.
What is the probability that the number is:
a) even
b) not even
c) less than 7
d) not less than 7
e) a prime number
f) not a prime number?
Show your answers as a fraction, decimal or percentage.
5
1
1
a)
0.5
b) 1
0.5
The prime numbers
1
0
2
2
between 1 and 10 are 2, 3,
6
3
6
1
0
6
4
c)
d) 1
1
0
5
1
0
1
0
1
0
1
0
5 and 7.
4
4
1
0
4
6
e)
40%
f) 1
60%
1
0
1
0
1
0
1
0
1
0
Example 2
The probability that Pran is late for school in the morning is 0.1.
a) What is the probability that he is not late for school?
b) How many times would Pran expect to be late in 20 mornings?
a) 1
0.1
0.9
b) 0.1
20
2. Pran would expect to be late twice in 20 mornings.
Exercise 3.1 ..........................................................................................
50 raffle tickets are sold, numbered 1–50. A ticket is chosen at random. What is the
probability that the number is:
a) even
b) less than 10
c) not less than 10
d) odd and divisible by 5
e) odd and divisible by 2
f) not number 6?
Show your anwers as percentages.
26
Maths Connect 2B
ADVERTISEMENT
0 votes
Related Articles
Related forms
Related Categories
Parent category: Education