Sample Question #110 (mathematical brainteaser)
My younger brother and I go to the same school. It takes me 20 minutes to walk to the school from home and it takes him 30 minutes. One morning, my brother takes off for school 5 minutes before I. After how many minutes of my walking will I catch up to my brother?
(Comment: according to an article in the New York Times a few months ago, a question similar to this one was asked of 8-year-old Terence Tao, a Chinese-Australian math prodigy who’s now a renowned mathematician at UCLA. He was able to figure out the answer in his head in no time! What a genius. Please try this on your own before peeking at my answer in the Comment section.)