From mathy mind-benders to eye-fooling illusions, here are 70 perplexing puzzles of every kind. But they all have one key thing in common—a wrong answer that seems so right! In Puzzle Me Twice, you’ll have to think—and think again—to overrule your first instinct and uncover the truth. For example:

If a hen and a half lays an egg and a half in a day and a half, how many eggs do half a dozen hens lay in half a dozen days?*

Bestselling author Alex Bellos wrangles math and physics, logic and wordplay, optical illusions, card games, and more to tie readers’ brains in pleasurable knots. It’s a merry tour of the many ways our reasoning can go wrong—and how we can be more fool-proof in the future. Puzzle on!

*Four times as many hens, over four times as many days, lay 16 times as many eggs: 1.5 × 16 = 24 eggs.