Discreet Mathematics Exercises #3:

15. What are all the possible remainders when you divide the square of an integer by 5? 16. Prove that the square root of an integer is either an integer or an irrational number. 17. Let d be the greatest common divisor of 102876 and 894. (a) Find d (b) Find integers a and y so that d = 102876 . 2 + 894 . y