How many positive 2-digit odd numbers can be formed using 0,1, 2, 3, 4, 5, 6, 7 without repetition?
13 21 31 41 see the pattern????
15 23 35 43
17 25 37 45
27 47
Total = 4 odds *3 each + 3 evens * 4 each = 12 + 12 = 24
