Question

In set-builder form.

A = {5, 10, 15, 20}

Answer 1

Answer:

• x : x is a natural number upto 20 and divisible by 5Hence, F = {x | x = 5n, n ∈ N, n < 4}

Answer 2

A = { x € n , x < 21 , x is a multiple of 5 }