Factors, Multiples and Prime Numbers

Tick ( √ ) the set which contains only factors of 24.

• 3    4    5
  

• 6    8    9
  

• 2    6    12
  

Tick ( √ ) around each number that has 2 and 3 as factors.

• 48 51 66

• 66 78 84

• 78 84 92

• 48 78 92

The multiples of an even number can be odd or even.

• True

• False

The factors of 39 are all odd.

• True

• False

The multiples of 4 are also the multiples of 2.

• True

• False

375 is not divisible by 25.

• True

• False

816 is divisible by 4.

• True

• False

Find the 2-digit prime numbers between 20 and 40, and whose sum of the digits is 11.

• 19

• 23

• 29

• 38

Find the 2-digit prime numbers between 20 and 30, and whose sum of the digits is divisible by 5.

• 19

• 23

• 37

• 41

Tara is thinking of a number.

The number is divisible by 4.

When 5 is added to the number, it becomes a prime number.

The number is greater than 20 but smaller than 30.

What number is Tara thinking of?