If the tens digit x and the units digit y of a positive integer n are reversed, the resulting integer is 81 more than n. What is y in terms of x ?  Options:
A) 10 - x B) 9 - x C) x + 9 D) x - 1 E) x + 1
Original Digits=xy i.e. Number=10x+y   After reversing the digits:   Digits=yx i.e. Number=10y+x   10y+x is 9 more than 10x+y   10x+y+81=10y+x   10x-x+81=10y-y   9x+81=9y   x+9=y   OR   y=x+9   Ans:x + 9
<result>C</result>
If the tens digit x and the units digit y of a positive integer n are reversed, the resulting integer is 81 more than n. What is y in terms of x ?