Divisibility

If a number divided by 7 the remainder is 6 and an another number divided by 7 the remainder is 1, then the sum of the two numbers is a multiple of 7.

• True

• False

• I don't know.

If one number divided by 7 the remainder is 6 and another number divided by 7 the remainder is 1, then the difference between the two numbers can be divided by 5.

• True

• False

• Maybe, but it's not sure.

• I don't know.

The 3*5*17 is

• multiple of 85

• multiple of 19

• even number

if a 5-digits number's last digit is 8, then

• the number may be divisible by 4.

• it's sure that the number is divisible by 4

• the number cannot be divisible by 4

If a number divided by 9 the remainder is 3, then

• the number is multiple of 3.

• it is not possible to decide whether the number is divisible by 3.

A number is divisible by 6 and 18. Then the number is divisible by 27.

• True

• False

• Maybe, but it's not sure.

• I don't know.

31 can be written as the sum of two prime numbers.

• False

• True, there are many ways

• True, but only one way

A number is divisible by 3, if

• the last digit is 3

• the last digit is divisible by 3

• the sum of the digits is divisible by 3

• the last two digits are divisible by 3.

Which statement is true?

A number is divisible by 2 and 3, then the number is

• divisible by 4

• divisible by 6

• divisible by 9

• not divisible by other numbers

5. Which statement is true?

A) There is no even prime

B) each prime number is odd

C) the 1 is prime number

D) 2 is the only even prime number

• A

• B

• C

• D