The product of two successive integral multiples of 5 is 300. Then the numbers are:

Let the consecutive integral multiple be $5n$and $5(n + 1)$ where n is a positive integer.

According to the question:

$5n \times 5(n + 1) = 300$

$\Rightarrow n^2 + n – 12 = 0$

$\Rightarrow (n – 3) (n + 4) = 0$

$\Rightarrow n = 3 and n = – 4.$

As$n$is a positive natural number so$n = – 4$will be discarded.

Therefore the numbers are 5n = 5 x 3 = 15

and 5(n + 1) = 5(3 + 1) = 20.