Wednesday 24 February 2016

mathematics - Can you find this abundant dad and his six prime sons?


We are six little prime brothers. All our ages add up to the age of our abundant and old dad who is obviously not in his prime.


However, if you pair him up with either of the prime neighbors, they can have a prime party.


Additionally, any five of our ages add up to a prime.


Deductive logic and small calculations might be enough to find us. Who are we?



Based on some initial comments, I will add few more comments: none of the brothers were born at the same time, and their dad is abundant and has seen all the Super Bowls since their inception.



Answer



The sons are



5, 7, 11, 19, 29, and 37. (All primes.)



The dad is



5+7+11+19+29+37 = 108 (an abundant non-prime number).
Any five of the sons' ages sum to a prime (71, 79, 89, 97, 101, and 103).

His neighbors are both primes (107 and 109).
The "parties" (concatenations of the father's age with a neighbor)
    are 108107 and 108109 — also primes.
Our virile father then sired his youngest at the venerable age of 103. Impressive!

To address the added comments, the sons' ages are all unique, the father's age is an abundant number, and the father is old enough to have seen the first Super Bowl in 1967.



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