Question

The sum of the digits of a two digit number is 9. Also, nine times this number is twice the number obtained by reversing the order of the digits. Find the number.

Answer 1

let two digit no. be tens place be x and ones place be y.
∴10x+y =9                              -(i)
9(10x+y)=2(10y+x)
90x+9y=20y+2x                      -(ii)
now solve i and ii

Answer 2

Here is your solution

Given :-

The sum of the digits of a two digit number is 9

Let
The digits be x and y, and the number be 10x + y.

I. e

x + y = 9 ------ (1)

Now
A/q

9×(10x + y) = 2×(10y + x)

90x + 9y = 20y + 2x

88x = 11y

y = 8x ---- (2)

putting the value of y in equation (1.) we get,

x + 8x = 9
9x = 9.
x = 1

y = 8×1 = 8.

Hence

The number is 10x +y = 10×1 + 8 = 18.

Hope it helps you