Question

the sum of 2 digit no is 9 .lf 27 is added to it ,the digits of no.get reversed. Find the no.​

Answer 1

Let the number be x, y

X+y=9.........1

(10x+y)+27=10y+x

10x-x+y-10y=-27

9x-9y=-27

X-y=-3............2

Add eq (1).and (2)

X+y=9

X-y=-3

............................

2x=6

X=3

Sub x=3 in eq (1) or (2)

X+y=9

3+y=9

Y=6

Answer 2

Let us assume, x and y are the two digits of the two-digit number

Therefore, the two-digit number = 10x + y  and reversed number = 10y + x

Given:

x + y = 9 -------------1

also given:

10x + y - 27 = 10y + x

9x - 9y = 27

x - y = 3 --------------2

Adding equation 1 and equation 2

2x = 12

x = 6

Therefore, y = 9 - x = 9 - 6 = 3

The two-digit number = 10x + y = 10*6 + 3 = 63