Question

Từ số 1 đến số 99 có bao nhiêu số lẻ chia hết cho 9

Khi viết các số trang của 1 quyển sách , bạn An phải dùng 900 chữ số hỏi quyển sách có bao nhiu trang

 

Answer 1

999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999996999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999599999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999099999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999

có câu hỏi tương tự ák