Answer:
Intrinsically motivated
Explanation:
Since Kevin was not enrolled in a school nor have a job that his mathematical reasoning would help him either pass a test or solve a problem at work, the reason for his motivation is driven by internal rewards. Hence Intrinsic motivation can be defined as a behavior, not driven by any external motivation, but by internal rewards. The motivation for Kevin wanting to learn mathematics on his own comes from within and is naturally satisfying to Kevin.
