Forced harmonic oscillator is usually treated in the freshman physics course albeit less mathematically than treated in our article. In any case, the concept of “resonance” explained there is very important and has wide applications in engineering. The second article treats the differential equation problem solved by former Korean child prodigy Ung-yong Kim in 1967 when he was four years old appearing on a Japanese TV show. I would not have been able to solve this problem myself if I hadn’t seen his solution on a blackboard.