Question: from 1 to 100 how many times 9 comes?
Answer: 9,19,29,39,49,59,69,79,89,90,91,92,93,94,95,96,97,98,99. You have not mentioned if only natural numbers must be considered while counting the number of 9s that appear between 1 and 100. If only natural numbers are considered while counting, then 9 appears 20 times.