Playing With Numbers

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

Without actual division, show that 11 is a factor of 1,10,011.

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

What are the possible factors of 

(a) 12

(b) 18?

Write first 3 multiples of 25.

What is the sum of any two?

(a) even numbers

(b) odd numbers

Write all the factors of the following number: 27

Write first three multiples of 11.

Write pairs of twin prime numbers less than 20.

Simplify: 18 + {1 + (5 – 3) x 5}