perplexus.info :: Numbers : Composite Total

Composite Total (Posted on 2009-03-31)

There is a composite number that's the sum of three 3-digit primes of the following sort: The first and the last digit are each 1-digit primes, and the first two digits taken together, as well as the last two digits taken together, are each 2-digit primes.

What are the three 3-digit primes that sum to the composite number in question?

Submitted by Charlie

Rating: 2.5000 (2 votes)

Solution: (Hide)

The only 3-digit primes that meet the criteria are:
313 317 373 797
The only set of three of these that add up to a composite are:
313 + 317 + 373 = 1003
Based upon "Prime furniture" by Adrian Somerfield, Enigma No. 1524, New Scientist, 13 December 2008.

Comments: ( You must be logged in to post comments.)

Subject	Author	Date
Puzzle Answer	K Sengupta	2024-01-31 07:13:37
solution	Jer	2009-03-31 10:58:13
solution	ed bottemiller	2009-03-31 10:57:09

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