Question

The digita of a 2 digit number differ by 5 . If the digits are interchanged and added to the original number we get 99 Find the original number .​

Answer 1

Heya!

let that two digit number be = xy

ACCORDING TO THE GIVEN QUESTION

x - y = 5 ... Equation i

10x + y + 10y + x = 99

11x + 11y = 99

x + y = 9 ... Equation ii

ADD BOTH THE EQUATIONS WE HAVE

2x = 14

x = 7

And

y = 2

So, the two digit number is 72

Answer 2

Let the one digit number be x

And tens digit number be y

(y>x)

No. 10y+x

And interchanged no. =10x+y

According to the question,

x-y=5.............¡

10y+x+10x+y=99

=>11y+11x=99

=>x+y=9..........¡¡

Now ¡¡-¡ we get,

x+y-(x-y) =9-5

=>2y=4

=>y=2

Putting y=2in equation ¡

x-y=5

=>x-2=5

=>x=7

The number is

10y+x=10×2+7=27