> There are three distinct digits that can be arranged to make product
> of two distinct primes. In fact, all six arrangements give the
> product of two distinct primes. Can you find the smallest of these
> numbers?
178.
(My first guess was 134, a near miss, as all the permutations are
products of two primes except the largest, which is the prime 431.)
--
Roger Phillips
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Ed,
I'm not sure if you're looking for the smallest of the digits, which is
1, or the smallest of the products, which is 178. It was a fun puzzle, but
I'm curious if there is an easier method than mine (I used Excel to do the
multiplying, then visually inspected the results).
Tom Clymer
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Ed,
I'm not sure if this is the question you asked, but the three digits
1,7, and 8 take in the six combinations all factor into a product of two
primes:
178 = 2 * 89
187 = 11 * 17
718 = 2 * 359
781 = 11 * 71
817 = 19 * 43
871 = 13 * 67
Kirk Bresniker
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178 =2*89
187=11*17
718=2*359
781=11*71
817=19*43
871=13*67
James L Melby
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178 is a solution.. any others?
great website,
Jason
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{1,7,8} isthe solution. So 178 is the answer
Les shader
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178
I made the assumption that 0 would not be allowed, since you say all six
arrangements of these digits are the product of two primes, and numbers
starting with 0 are usually not allowed. That means there are only 84
possible sets of digits. Searching by hand starting from 123 found the
solution fairly quickly.
--
Eric Backus
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178
Andrew Lord
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178
One of the permutations is a movie title.
(One Eight Seven)
Bryce Herdt
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178 = 2 * 89
187 = 11 * 17
718 = 2 * 359
781 = 11 * 71
817 = 19 * 43
871 = 13 * 67
Colin Sturm
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