Write five pairs of prime numbers less than 20, whose sum is divisible by 5.

2

(a)

Using divisibility tests, determine the following number is divisible by 6? 297144

2

(a)

Using divisibility tests, determine the following number is divisible by 6? 639210.

2

(a)

Using divisibility tests, determine the following number is divisible by 6? 17852

2

(a)

Find the LCM of 15 and 20.

2

(a)

Express each of the following as the sum of three odd prime numbers. 49

2

(a)

Find the HCF of the following numbers using prime factorisation method 72,108,180

2

(a)

Find the HCF of the following numbers, using division method. 58,70

2

(a)

In each of the following numbers, replace * by the smallest number to make it divisible by 9. 65*5

2

(a)

In each of the following numbers, replace * by the smallest number to make it divisible by 9. 2*135

2

(a)

Give the prime factorisation of each of the following number: 4335

2

(a)

Give the prime factorisation of each of the following number: 2907

2

(a)

Find the least number of five digits that is exactly divisible by 16, 18, 24 and 30.

2

(a)

Three measuring rods are 45cm, 50cm and 75cm in length. What is least length (in m) of a rope that can be measured by the full length of each of these three rods?

2

(a)

Try this for the numbers (a) 8 (b) 12

2

(a)