Question

the sum of the digits of a two digit number is 15. The number obtained by interchanging its digits the given number by 9 . find the original number. ​

Answer 1

Answer:

Let the units digit be x and tens digit be y.

Then, x+y=15 ……….(i)

Given number: 10y+x

Interchanged digits: 10x+y

A.t.Q:-

⇒(10x+y)−(10y+x)=9

⇒10x+y−10y−x=9

⇒9x−9y=9

⇒x−y=1 ………(ii)

Solving (i) and (ii)

x=8, y=7

∴ Two digit number=78

Answer 2

Step-by-step explanation:

Let the tens and the units digits of the required number be x and y, respectively. Hence, the required number is 78.