原題綠皮書 Ch2 Brain TeasersYou have two ropes, each of which takes 1 hour to burn. But either rope has different densities at different points, so theres no guarantee of consistency in the time it takes different sections within the rope to burn. How do you use these two ropes to measure 45 minutes?中文題意你有兩根編子每根燒完恰好1小時但密度不均勻燒一半長度不等于過了半小時。如何精確測量45分鐘解答核心洞察一根繩子兩頭同時點燃無論密度如何一定30分鐘燒完。速度×2時間÷2。操作步驟t0繩A點熔兩始繩B只點燃一端同時開始。t30min繩A燒完。立刻點燃繩B的另一端。t45min繩B燒完。剩余30min的量兩頭燒15min燒完。答案301545分鐘。#量化面試 #Quant #BrainTeaser #逆向思維 #創造性思維