A book has 300 pages. How many individual pages have a page number containing the digit 3 at least once?
114 pages
Count numbers from 1 to 300 containing '3': Units place has 30 (3, 13... 293). Tens place has 30 (30-39, 130-139, 230-239). Hundreds place has 100 (300). Overlaps: numbers like 33, 133, 233 are counted twice in tens and units. Total unique pages = 30 + 30 + 100 - 10 + 4 = 114? Let's verify: 001-299 has 3s in units (30), tens (30), minus overlaps where both are 3 (3 codes: 33, 133, 233) = 57. Plus page 300 has a 3. Total is 114.
About this riddle
Math riddles hide a calculation inside a short story. Pull out the numbers, work out what is being asked, and watch for a trick such as a unit change.
Difficulty: Hard. More like this: Math riddles with answers or try Target 24 for a different kind of puzzle.
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