If you write down all the whole numbers from 1 to 100 inclusive, how many times will you write the digit 7?
20 times
The digit 7 appears in the units place 10 times (7, 17, 27... 97) and in the tens place 10 times (70, 71, 72... 79). 10 + 10 = 20.
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: Medium. More like this: Math riddles with answers or try Target 24 for a different kind of puzzle.
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