Question

The sum of the digit of a two digit number is 9. The number obtained by interchanging the digit is 63 more than the original no.?​

Answer 1

tens digit be x and unit digit be y. then x+y=9.also original no. = 10x+y.now 10y+x=63+10x+y. by solving it you will get the answer

Answer 2

LET THE UNITS DIGIT BE X AND TENS DIGIT BE Y

ORIGINAL NUMBER= 10Y+X

A.T.Q

X+Y=9. ----------------------EQUATION 1

NUMBER OBTAINED BY INTERCHANGING THE DIGIT=10X+Y

10X+Y-(10Y+X)=63

10X+Y-10Y-X=63

9X-9Y=63

9(X-Y)=63

(X-Y)=7. ---------------------EQUATION 2

THEREFORE WHEN WE SOLVE THE EQUATION

THE VALUE OF X IS 8 AND THE VALUE OF Y IS 1

HENCE THE ANSWER IS 18