A mathematician walking leisurely down a street on a Sunday afternoon spotted a colleague he had not seen for some time.<\/p>\n
\u201cHello Fred, nice to see you.<\/p>\n
\u201cLikewise, Leonard, I see you are well,\u201d replied Fred, shaking his hand. \u201cDid you ever marry Helen?\u201d<\/p>\n
\u201cYes, I did and now we have three children,\u201d replied Leonard.<\/p>\n
\u201cGlad to hear it. How old are your children,\u201d asked Fred.<\/p>\n
\u201cAs you are a colleague, I will give you the answer in a mental package,\u201d smiled Leonard.<\/p>\n
\u201cOk, hand it over,\u201d said Fred.<\/p>\n
\u201cWell, the sum of their ages is a perfect number. Twenty-one times Sarah\u2019s age is the ninth heptagonal number. The product of their ages is a number whose double cross sum is nine. Jason is five years younger than Alex. Is that sufficient information for you,\u201d chuckled Leonard.<\/p>\n
\u201cMore than sufficient,\u201d replied Fred and promptly gave Leonard their correct ages.<\/p>\n
\u201cNext time I see you, I will also set you a small task,\u201d laughed Fred and invited Leonard to come along to his favorite inn to discuss old times.<\/p>\n