Question

the sum of the digits of a two-digit no. is 12. The no. obtained by interchangeing it's exceeds the given no. by 18. find the no.​

Answer 1

57.
You can verify the answer if you want.

Answer 2

Answer:

original no. was 57

explanation given

Step-by-step explanation:

let digit at tens place be x and at ones place be y,

then

original no. = 10x + y = 12 (a no. is of form 10n +m)

new no. = 10y + x = 10x + y + 18

solution

10y + x = 10x + y + 18

9y - 9x = 18

9(y-x) = 18

y-x = 2

adding x at both sides

y - x + x = 2 + x

(y + x) = 2 + 2x. ( given that x+y = 12)

12 = 2(1 + x)

x + 1 = 6

x = 5

so

y = 12 - x

y = 7

therefore,

original no. = 10x + y = 10(5) + 7 = 57

Hope it helps