Recall that z15 = {0, 1, 2, . . 14}, where addition and multiplication are defined modulo 15.
find x, y? z15 such that xy = 0 but x/= 0, y? /=0 (where xy is the product in z15.) find a condition on m such that xy = 0 in zm implies that either x = 0 or y = 0

Lems1. the following data set represents the scores on intelligence quotient(iq) examinations of 40 sixth-grade students at a particular school: 114, 122, 103, 118, 99, 105, 134, 125, 117, 106, 109, 104, 111, 127,133, 111, 117, 103, 120, 98, 100, 130, 141, 119, 128, 106, 109, 115,113, 121, 100, 130, 125, 117, 119, 113, 104, 108, 110, 102(a) present this data set in a frequency histogram.(b) which class interval contains the greatest number of data values? (c) is there a roughly equal number of data in each class interval? (d) does the histogram appear to be approximately symmetric? if so,about which interval is it approximately symmetric?