Question 935663
lets group the numbers into groups of 0-9, 10-19, 20-29, 30-39, 40-49 ...
in group 0-9 there is only 1 three used: 10-19 (1): 20-29(1): 30-39(11) : 40-49(1) : 50-59 (1): 60-69(1): 70-79(1): 80-89(1): 90-99 (1) =:***There are a total of 20 threes used from 1-99 pages.
now we are only have 17 threes left, so count 17 threes from each group and you will get to number 163. At number 163, all the threes are used. after 163, numbers 164-172 do not use the number three again so the number of pages she can do total is 172 pages with no leftovers of threes.