There are two urns, each with some numbered cards inside.
In urn A there are cards representing all 3-digit numbers (from 109 to 910 inclusively), having 10 as their sum of digits.
In urn B - all 3-digit numbers (from 119 to 920 inclusively), with 11 as their s.o.d.

Assuming you aim to randomly draw a prime number, which urn would you choose?
What if there was a 3rd urn with s.o.d=15, would you consider it as a good choice?

(In reply to re(2): computer assisted solution by Charlie)

127  should be in the 1st list-

maybe there other numbers missing ???

I did not check further - please debug....

Edited on January 11, 2013, 1:16 am

Posted by Ady TZIDON on 2013-01-11 01:14:02