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Pro Problems > Math > Number and Quantity > Number Theory > Divisors

Featured Pro Problems

Greatest common factor and least common multiple problem
Find a number, given its LCM and GCF with another integer
Determine how many stairs the staircase has, based on what happens when people leap up the stairs
Find how many multiples of two and three there are between two integers
Find how many integers are multiples of two and three, but not six.
Find the pattern. Study the list of numbers, and figure out what number is missing, and why
A problem involving dividing donuts evenly among a group of people
Factor the following number without use of your calculator

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Divisor Count, Donut Division, Find the Missing Number, GCF and LCM, LCM and GCF, Leaping up the Obelisk, Multiples of Two and Three, No-Calculator Factoring, Two, Three, but not Six

Understanding Coronavirus Spread

A Question and Answer session with Professor Puzzler about the math behind infection spread.

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