# Starbucks

Question: How much does the Starbucks in Times Square bring in, in annual revenue? . . C A P T A I N I N T E R V I E W . . Solution: Even for an insanely busy Starbucks, you can get pretty far by estimating the average ticket cost and the average … Continue reading Starbucks

# Points

Question: How many points are there on the globe where, by walking 10 miles south, 10 miles east, and 10 miles north, you reach the place where you started? . . C A P T A I N I N T E R V I E W . . Solution: We know that the North … Continue reading Points

# Bowling ball

Question: Your job is bowling ball tester. You have two identical bowling balls. Given a 100-story building, your challenge is to figure out from which floor a dropped bowling ball will shatter on the ground. You know nothing about the durability of the bowling balls; they may be very fragile and shatter when dropped from the … Continue reading Bowling ball

# 12 balls

Question: You have 12 balls. All of them are identical except one, which is either heavier or lighter than the rest. The odd ball is either hollow while the rest are solid, or solid while the rest are hollow. You have a scale, and are permitted three weighings. Can you identify the odd ball and … Continue reading 12 balls

# Soda cans

Question: Why are soda cans cylindrical? . . C A P T A I N I N T E R V I E W . . Answer: To allow easier gripping. To allow easier, denser packing in dispensing machines. To avoid sharp edges that might cut hands. Circular surfaces can easily distribute internal pressure. In … Continue reading Soda cans

# The Sofa Problem

Question: Say you're moving into a new house. You've just finished U-Hauling your furniture over, and are in the process of setting up your sofa in the living room. There's just one problem. The hall to the living room has a 90-degree turn to it. No matter how hard you push, you can't get your sofa … Continue reading The Sofa Problem