AMC 8 Number Theory & Divisibility

Question 1

What is the greatest common factor (GCF) of 48 and 36?

Accepted Answer

12

Answer

6

Answer

9

Answer

18

Question 2

Which of the following is a prime number?

Accepted Answer

61

Answer

51

Answer

57

Answer

63

Question 3

What is the least common multiple (LCM) of 6 and 8?

Accepted Answer

24

Answer

12

Answer

16

Answer

48

Question 4

How many positive factors does 36 have?

Accepted Answer

9

Answer

6

Answer

7

Answer

8

Question 5

What is the sum of all positive factors of 12?

Accepted Answer

28

Answer

24

Answer

30

Answer

32

Question 6

If a number leaves a remainder of 3 when divided by 7, what remainder does twice that number leave when divided by 7?

Accepted Answer

6

Answer

3

Answer

5

Answer

1