Reversed digits

[espyn]

If the tens digit x and the units digit y of a positive integer n are reversed, the resulting integer is 9 more than n. What is y in terms of x ?
(A) 10 - x
(B) 9 - x
(C) x + 9
(D) x - 1
(E) x + 1

[espyn]

Nevermind I know this one.

10x + y - 10y + x = 9
9x - 9y = 9
x- y = 1
x - 1 = y

Answer is D.

[YankeeMusk]

Is'nt (E) the Official Answer ??


10y+x-(10x+y) = 9
10y+x-10x-y = 9
9y-9x = 9
y = 1+x

[ckpankaj]

Agree E

[espyn]

you are correct. thanks.

[nikiforos]

My ans is x + 1 i.e. E

10x + y + 9 = 10y + x
solve to get
y = x + 1

[tanmoy]

10y+x-10x-y=9

solving this , get y= x+1.

ans E

[MTG123]

Another vote for E

[prreeet]

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