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BrainTwister #6: Factor factory

Can you solve this week’s logic puzzle? Plus our quick quiz and the answer to last week’s problem

By New Scientist

7 February 2024

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#6 Factor factory

Set by Daniel Griller

The factors of 12 are 1, 2, 3, 4, 6 and 12. It has four even factors and two odd factors, so two-thirds of its factors are even.

What fraction of the factors of 8 are even?

How many whole numbers between 1 and 100 have the property that exactly half of their factors are even?

How many whole numbers between 1 and 1 million have the property that exactly one-third of their factors are divisible by 3?

Solution next week

#5 Diagonal lines

Solution

Generally, for a shape with n vertices, there…

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