Factors and multiples of a number

If N is natural number A= Factors of N} and B{Multiples of N} , then n(A cap B)=_____.

The number of multiples of a given number is finite.

Study the given statements carefully. State T for true and 'F' for false and select the correct option. (i) If a number is a factor of each of the given two numbers, then it must be factor of their a difference. (ii) If a number is divisible by another number, then it must be divisible by each of the factors of that number. (iii) If a number is divisible by another number, then it is also divisible by all the multiples of that number. (iv)No prime number other than 2 is even but every odd number is necessarily a prime number.

Property 8 The number of multiples of a given number is infinite.

What will be the ratio of Highest common Factor and Least Common Multiple of two numbers 16 and 20?

What will be the ratio of Highest common Factor and Least Common Multiple of two numbers 14 and 18?