Question

A number consists of two digits whose sum is 9.If 27 is subtracted from the number its digits are reversed.Find the number.

Answer 1

The number is 72.
7+2=9
and it is reverse of 27.

Answer 2

let the digit at ones place be x
then, the digit at tens place =9- x
number so formed = 10(9-x)-x = 90-10x + x
= 90-9x
no. formed by interchanging digits = 10x+9-x
= 9x+9
A/Q=
(90-9x) - 27 = 9x+9
= 90-9x - 27 =9x+9
=43-7=9x+9x
=36 = 18x
= x = 36/18 = 2
hence, the no. is 70-9x = 70-9*2
= 70-18 = 52.