Playing With Numbers

Write all the factors of the following number: 27

If the LCM and HCF of any two numbers are 15 and 4 respectively, find the product of the numbers.

What are the possible factors of 

(a) 12

(b) 18?

Find LCM of 60 and 40.

Find the H.C.F of the following numbers. 27, 63

List all the multiples of 7 that lie between 125 and 142.

Write pairs of twin prime numbers less than 20.

Write first three multiples of 11.

Find the HCF of 5 and 7.

Simplify: 18 + {1 + (5 – 3) x 5}