Send me how many books you have
or
Send me whatever book you have.
My concern is about quantity of book, so which of these both sentences is correct?
Send me how many books you have
or
Send me whatever book you have.
My concern is about quantity of book, so which of these both sentences is correct?
Neither.
"Send me how many books you have" is close but implies sending the actual books, not their quantity. I would suggest "Tell me how many books you have".
"Send me whatever book you have" is also about sending an actual book, but leaves the sender to choose which book to send.