Problem Solving (PS) | Re: What is the total number of positive integers that are less

how many numbers less than 100 don't have a 2 or 5 as a factor? List out the all the numbers to 50 that work. Once you're half way, you'll notice 20 numbers work. Double that for the "less than 100" goal and you get 40 or b.

1 3 7 9 11 ->5
13 17 19 21 23 -> 10
27 29 31 33 37 -> 15
39 41 43 47 49 -> 20

Statistics : Posted by Fish181 • on 24 Feb 2012, 23:11 • Replies 8 • Views 22855

---