Question

nines times a two digit natural number is the same as twice the number obtained by interchanging the digits of the number. If one digit of the number exceeds the other number by 7 find the number

Answer 1

let unit's place and the largest number be 'x'
and tens place and the smallest number be 'y'

therefore number=10y+x
according to the question

9(10y+x)=2(10x+y)
90y+ 9x=20x+ 2y
90y-2y=20x-9x
88y=11x
8y=x.......(1)

&
y+7= x
y+7=8y. [ from eq (1)]
7=7y
**y=1**

putting value of y in eq 1
8×1=x
**x=8**

hope it is helpful for you