10 apples cost --

Yesterday, for fun I asked kittsy:
"If 5 apples cost 5 Rupees, how much does 1 apple cost?"
She replied: "one rupee"
I was awestruck. Jay couldn't believe it either. We have twisted the question and asked her:
"If one apple cost 1 Rupee, how much does 10 apples cost?" She coolly said: "ten rupees". WOW!
I believe she atleast reasoned and mapped the following way:
5 is 5
so 1 is 1
similarly 10 must be 10.