Solve this question 4

Question 4 (10 points) Books are identified by an International Standard Book Number (ISBN-10), a 10 digit code. The first 9 digits identify the language, the publisher, and the book. The tenth digit is a check-sum digit, which is determined by the following modulo 11 congruence 9 C 10 = kxk mod 11 k=1 Here xx denotes the k th digit. The possible digits are {0,1,2,3,4,5,6,7,8,9,X} where X denotes 10. Suppose the first 9 digits of the ISBN of your book are 0-252-72548 (ignore dashes). What is the 10th digit? A