Primes, Factors, Multiples Flashcards
1
Q
List the prime numbers up to 20.
A
2, 3, 5, 7, 11, 13, 17, 19
2
Q
Write 30 as a product of primes.
A
2 x 3 x 5
3
Q
Write 28 as a product of primes.
A
2 x 2 x 7
4
Q
What is the prime factor decomposition of 45?
A
3 x 3 x 5
5
Q
What is the highest common factor of 12 and 15?
A
3
6
Q
What is the highest common factor of 24 and 28?
A
4
7
Q
What is the highest common factor of 36 and 60?
A
12
8
Q
What is the highest common factor of 90 and 30?
A
30
9
Q
What is the lowest common multiple of 12 and 15?
A
60
10
Q
What is the lowest common multiple of 4 and 13?
A
52
11
Q
What is the lowest common multiple of 9 and 12?
A
36
12
Q
What is the lowest common multiple of 8 and 20?
A
40
13
Q
Express 120 as a product of primes.
A
2 x 2 x 2 x 3 x 5
14
Q
Give a prime number between 40 and 50
A
41, 43, 47
15
Q
Give a prime number between 20 and 30
A
23, 29
