Download Lottery probability

Lottery probability
The National Lottery picks six balls out of a set
numbered 1–49.
Answer these questions using fractions, simplifying
where appropriate.
14
29
03
1. What is the probability that the first ball picked will be...
a. the number 25
b. an even number
c. a prime number
d. an even prime number
e. a multiple of 3
f. a multiple of 7 and greater than 28
g. a factor of 28
h. a number from the Fibonacci sequence?
2. If the first ball chosen is the number 49, what is the probability that the next ball
will be:
a. a consecutive number
b. an even number?
3. If the first ball chosen is number 2, what is the probability that the next ball will be
a consecutive number?
4. If the first ball chosen is number 2, and the next is number 3, what is the probability
that the next ball will be a consecutive number?
5. If the first 5 balls picked are all even, what is the probability that the next ball
picked will be even?
6. Which of these sets of six balls is more likely to be picked:
a. 1, 2, 3, 4, 5, 6
b. 2, 4, 6, 8, 10, 12
c. 4, 42, 36, 16, 24, 29?
Explain your answer.
© www.teachitmaths.co.uk 2011
16611
Page 1 of 2
Lottery probability
Answers
1.
a. 1/49
b. 24/49
c. 15/49 (the prime numbers are 2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43,
47)
d. 1/49
e. 16/49
f. 3/49
g. 6/49 (factors of 28: 1, 2, 4, 7, 14, 28)
h. 8/49 (Fibonacci sequence: 1, 1, 2, 3, 5, 8, 13, 21, 34)
2.
a. 1/48
b. 24/48 = ½
3.
2/48 = 1/24
4.
2/47
5.
19/44
6.
All the sets are equally likely to be picked.
© www.teachitmaths.co.uk 2011
16611
Page 2 of 2