Question

Find two consecutive natural numbers whose product is 20.

Answer 1

Let a natural number be x.

The next number = x + 1

x (x + 1) = 20

x² + x – 20 = 0

(x + 5)(x – 4) = 0

x = -5, 4

∴ x = 4 (∵ x ≠ -5, x is natural number)

The next number = 4 + 1 = 5

Two consecutive numbers are 4, 5