A math professor has just been knocked down by a speeding car. A police officer rushed over and asked，"Were you able to get the license¹ number of the vehicle that hit you，sir?”

一位数学教授被一俩时速很快的车撞倒了。警察跑过去问:“先生，您能说出撞您的那辆车的车牌号码吗?”

The professor replied，"Well，not exactly，but I do recall that if the number was multiplied by itself，then divided by three，the square root of the answer would turn out to be the original number with the integers reversed.”

教授回答:“嗯，我说不准，可是我记得，如果将号码自乘，再除以三，然后开方，则平方根正好同原数的次序颠倒过来。”