Jack has always enjoyed solving problems, whether it involved putting a puzzle together or learning how to create a website. His chief personality type according to Holland is likely to be:

Investigative

Explanation: According to Holland, there are six  personality types which include: Realistic, Investigative, Artistic, Social, Enterprising, and Conventional.

Our interest here is the Investigative type of personality individuals  who use abstract and logic intelligently  to solve  problems. These individuals in this group  love to work independently and  enjoy puzzle- like challenges  that employ  critical thinking and intellect, making them love the maths and sciences and mostly end up in professions like Computer scientist, doctors, mathematicians etc

Here Jack who loves solving problems chief personality type according to Holland is likely to be Investigative.

good question. i'll be looking into that. (this is a joke sir)

i believe the answer is: returns on investments, no wages

people who belong in upper class society would most likely get there by obtaining multiple source of income, which a certain percentage of ownership for businesses. since most of them are job creator, they would most likely get their money from profit, not wages.