Question 453287
The number is 0.36.

Let x be the tens place, y the ones place.

Then x + y = 9, and 10x + y + 27 = 10y + x

==> 27 = 9y - 9x <==> y - x = 3

y - x = 3
y + x = 9

==> 2y = 12
y = 6 ==> x = 3.

The decimal number is 0.36.