Derrick Niederman, one of Sterling's most popular puzzle authors, has come up with another collection of super-tricky math brainteasers that's great for home or the classroom. Hours of mind-bending, brain-stretching fun await solvers, who can warm up with easy problems like this, before moving on to harder and harder conundrums: Hector can run from the train station to his parents' house in eight minutes. His younger brother Darius can run the same...