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Vamshi Jandhyala

Books ·HTML edition

The Riddler

Problems from FiveThirtyEight, modelled and solved

275 chapters · About the book

  1. 1 The Honest Prince and the Rancher’s Children
  2. 2 Can You Knock Down The Last Bowling Pin?
  3. 3 Can You Find Your Pills?
  4. 4 Can You Make Room For Goats?
  5. 5 How Long Will Your Smartphone Distract You From Family Dinner?
  6. 6 Will The Neurotic Basketball Player Make His Next Free Throw?
  7. 7 Night Falls. A Storm Rolls In. Can You Cross The River?
  8. 8 How Many Cars Will Get Stuck In Traffic?
  9. 9 Will Someone Be Sitting In Your Seat On The Plane?
  10. 10 Should You Pay $250 To Play This Casino Game?
  11. 11 Should You Shoot Free Throws Underhand?
  12. 12 Can You Slay The Puzzle Of The Monsters’ Gems?
  13. 13 Can You Solve This Elevator Button Puzzle?
  14. 14 The Puzzle Of Misanthropic Neighbours
  15. 15 You Have $1 Billion To Win A Space Race. Go.
  16. 16 Should The Grizzly Bear Eat The Salmon?
  17. 17 How Long Will It Take To Blow Out The Birthday Candles?
  18. 18 Who Steals The Most In A Town Full Of Thieves?
  19. 19 Pick Up Sticks And Help A Frogger Out
  20. 20 How Do You Like Them Rectangles?
  21. 21 Will You Be A Ghostbuster Or A World Destroyer?
  22. 22 Palindrome Senates and an Ancient Tiling
  23. 23 Where Will The Seven Dwarfs Sleep Tonight?
  24. 24 Help Us Find These Missing Pieces
  25. 25 When Will The Arithmetic Anarchists Attack?
  26. 26 World Cup Standings and Number Shuffling
  27. 27 Can You Win The Token Game?
  28. 28 What Share Of Your Gummy Vitamins Are The Right Flavor?
  29. 29 The Eternal Question: How Much Do These Apricots Weigh?
  30. 30 What Are The Odds You’d Already Have My Number?
  31. 31 What Comes After 840? The Answer May Surprise You
  32. 32 How Low Can You Roll?
  33. 33 How Many Ways Can You Raid The Candy Shop?
  34. 34 Who Wants To Be A Riddler Millionaire?
  35. 35 Can You Track The Delirious Ducks?
  36. 36 Can You Find A Number Worth Its Weight In Letters?
  37. 37 Can You Solve The Vexing Vexillology Of Spelling Bee?
  38. 38 Can You Find A Matching Pair Of Socks?
  39. 39 Can You Get A Haircut Already?
  40. 40 How Good Are You At Guess Who?
  41. 41 What Is The First Flipper’s Advantage?
  42. 42 Can You Find The Best Dungeons & Dragons Strategy?
  43. 43 Can You Tell When The Snow Started?
  44. 44 Can You Flip The Magic Coin?
  45. 45 When Is The Next Centered Pentagonal Flag?
  46. 46 Breaking A Slide Rule Into Four Pieces
  47. 47 Can You Reach The Summit First?
  48. 48 How Close To The Bullseye Can Robin Get?
  49. 49 Can You Hunt For The Mysterious Numbers?
  50. 50 Can You Skillfully Ski The Slopes?
  51. 51 How Far Down Does The Little Cube Reach?
  52. 52 Can You Randomly Move The Tower?
  53. 53 Can You Cross Like A Boss?
  54. 54 En Garde! Can You Win The Fencing Relay?
  55. 55 Can You Slice The Ice?
  56. 56 Can You Stick It To The Genie?
  57. 57 How Many Friends Are On The Riddler Social Network?
  58. 58 Can You Survive Squid Game?
  59. 59 Who Betrayed Dune’s Duke Leto?
  60. 60 Can You Climb Your Way To Victory?
  61. 61 Can You Bake The Radish Pie?
  62. 62 Can You Get The Paper Cut?
  63. 63 Can You Draft A Riddler Fantasy Football Dream Team?
  64. 64 Can You Catch The Cricket?
  65. 65 Are You Clever Enough?
  66. 66 Will Riddler Nation Win Gold In Archery?
  67. 67 Can You Hop Across The Chess Board?
  68. 68 Can You Win The Penalty Shootout?
  69. 69 Can You Solve This Astronomical Enigma?
  70. 70 Can You Decipher The Secret Message?
  71. 71 Can You Crack The Case Of The Crystal Key?
  72. 72 No Isosceles Triangles For You!
  73. 73 Can You Systematically Solve A Friday Crossword?
  74. 74 Can You Cut The Perfect Pancake?
  75. 75 Can You Crack The Case Of The Crescent Moon?
  76. 76 Can You Navigate The One-Way Streets?
  77. 77 Can You Find An Extra Perfect Square?
  78. 78 Can You Bake The Biggest Pie?
  79. 79 Can You Bat .299 In 299 Games?
  80. 80 How Many Ways Can You Build A Staircase?
  81. 81 Can You Win Riddler Jenga?
  82. 82 Can You Find The Luckiest Coin?
  83. 83 Work A Shift In The Riddler Gift Shop
  84. 84 It’s Elementary, My Dear Riddler!
  85. 85 Can You Fold All Your Socks?
  86. 86 Can You Salvage Your Rug?
  87. 87 Can You Make The Fidget Spinner Go Backwards?
  88. 88 When Will The Fall Colors Peak?
  89. 89 Can You Knock Down The Gates?
  90. 90 How Many Turkey Trotters Can You Pass?
  91. 91 Can You Win The Riddler Football Playoff?
  92. 92 Random Walk from the Centre of a Unit Square and Cube
  93. 93 What’s The Best Way To Drop A Smartphone?
  94. 94 Which Geyser Gushes First?
  95. 95 How Long Before You Can Use Your 2015 Calendar Again?
  96. 96 How Badly Can A Car Salesman Swindle You?
  97. 97 Who Will Win The Politicians’ Secret Vote?
  98. 98 Will The Dog Catch The Duck?
  99. 99 Can You Decode The Four Secret Messages?
  100. 100 Can You Win This Hot New Game Show?
  101. 101 Can You Best The Mysterious Man In The Trench Coat?
  102. 102 Can You Solve The Impossible Puzzle?
  103. 103 Can You Solve This Napoleonic Puzzle?
  104. 104 The Perplexing Puzzle Of The Proud Partygoers
  105. 105 Can You Solve The Puzzle Of The Overflowing Martini Glass?
  106. 106 Can You Solve The Puzzle Of The Baseball Division Champs?
  107. 107 Can You Solve The Puzzle Of The Pirate Booty?
  108. 108 Solve The Mystery Of The Mathematical Mistakes
  109. 109 Can You Solve The Puzzle Of The Picky Eater?
  110. 110 What If Robots Cut Your Pizza?
  111. 111 Can You Figure Out How To Beat Roger Federer At Wimbledon?
  112. 112 Can You Save Riddler Headquarters From Laser Larry?
  113. 113 How Long Will You Be Stuck at the Bar?
  114. 114 Stop the Alien Invasion
  115. 115 Sniff Out the Traitorous Generals
  116. 116 The Pokémon Go Trainer’s Round Trip
  117. 117 Outrun the Angry Ram
  118. 118 The Particular Mathematician’s Cake
  119. 119 Bananas to the Bazaar
  120. 120 Who Keeps the Money on the Floor?
  121. 121 How High Can the Count Count?
  122. 122 The Carpenter’s Circular Table
  123. 123 Cubs Win-Strings and a Risk-Free Bet
  124. 124 Pawns, Knights, and Fairy Pieces
  125. 125 Flipping Coins and a Deadly Board Game
  126. 126 Growing Words and a Point-Rich Boggle Board
  127. 127 A Rickety Bridge and One Decisive Vote
  128. 128 Couples in a Line and the Lonesome King
  129. 129 Championship Droughts and Secret Santas
  130. 130 A Suspicious Tournament and a Gold-Hungry War
  131. 131 Misplaced Rocks and Tangled Wires
  132. 132 Scaling a Death Star and Outgunning Stormtroopers
  133. 133 A Doomed Solitaire and Baby Poker
  134. 134 A Reusable Calendar and the Game of Hip
  135. 135 Tetris Tilings and a Splitting Microbe
  136. 136 The Lifeguard’s Dash and Toddler Poker
  137. 137 Counting Honest Politicians and Burning Ropes
  138. 138 Two Mysteries of the Gold Coins
  139. 139 The Biggest Number and the Corn Maze
  140. 140 Who Will Win the Space Race?
  141. 141 The Toddler at the Couch and the Ten Dwarves
  142. 142 Lunch in the Park and the Crowded Chessboard
  143. 143 Two Cards at Lunch and the Multiplication Game
  144. 144 Bingo Cards and the Empty Supreme Court
  145. 145 Temperature Records and Picking The Highest Card
  146. 146 Three Hat-Wearing Logicians and Four Repainting Balls
  147. 147 Mrs. Perkins’s 13-by-13 Quilt and the Lucky Derby
  148. 148 Carpool Tickets
  149. 149 Best-Of-Seven and the First-Price Auction
  150. 150 The Barron Square and Four Sealed Checks
  151. 151 Three Birthday Pairs and Chaos Tag
  152. 152 Letter-Lengths and the Caffeine Contest
  153. 153 Pursuit on the Shore and Ranking Films
  154. 154 Crescents, Footballs, and the Squishyball Series
  155. 155 Ballots, Primaries, and the Spy in Riddler Nation
  156. 156 Lowest Unique Number and the Factor Chain
  157. 157 Is This Bathroom Occupied?
  158. 158 Can You Plug The White House Leak?
  159. 159 Can You Unravel These Number Strings?
  160. 160 Is Your Friend Full Of It?
  161. 161 Four Aces Against The Deck
  162. 162 Rock, Paper, Scissors, Double Scissors
  163. 163 Three Daughters And One Hundred Boxes
  164. 164 A Perfect Game Of Jeopardy And A Game Of Coinball
  165. 165 Can You Please The Oracle? Can You Escape The Prison?
  166. 166 The Twenty-Five Horses And The Price Is Right
  167. 167 Four Puzzles From Riddler Nation’s Students
  168. 168 Inside The Cube And The Three-Lock Safe
  169. 169 The Perfect Darts Game
  170. 170 The Count Counts Higher, and Equations Hidden in Digits
  171. 171 Two Holiday Puzzles
  172. 172 A Triangle, A Tetrahedron, And A Circle’s Centre
  173. 173 Picture Frames That Crash To The Floor
  174. 174 The Dodgeball Truel
  175. 175 Doppler Cars and Conway’s Shuffle
  176. 176 Yahtzee Strategy
  177. 177 Bollier Numbers
  178. 178 Nightmare Klondike
  179. 179 Shut the Box
  180. 180 How To Cross The Street
  181. 181 How Fast Can You Type A Million Letters?
  182. 182 Pirates, Monkeys, and Coconuts
  183. 183 How Hard Is It To Find A Running Buddy?
  184. 184 When Will Your House Collapse? Should You Take A Construction Contract?
  185. 185 The Case Of The Smudged Secret Message
  186. 186 How Many Phones Do You Need To Win HQ Trivia?
  187. 187 The Riddler’s Inaugural Rock-Paper-Scissors Tournament
  188. 188 What Are The Odds World Cup Teams Play Each Other Twice?
  189. 189 How Fast Can You Deliver PB&Js? How Many Meerkats Can Survive?
  190. 190 Can You Slice This In Half?
  191. 191 Damn The Torpedoes, Two Puzzles Ahead!
  192. 192 The Perfect Doodle Puzzle To Keep You Busy During Boring Meetings
  193. 193 Where On Earth Is The Riddler?
  194. 194 Step 1: Game Theory. Step 2: Step 3: Profit!
  195. 195 How Many Hoops Will Kids Jump Through To Play Rock, Paper, Scissors?
  196. 196 The New National Pastime: Competitive Coin Flipping
  197. 197 I’d Like To Use My Riddler Lifeline
  198. 198 To Solve The Eccentric Billionaire’s Puzzle, You Must First Defeat The Banker
  199. 199 Two Paths Diverged In A City And I, I Took The Block Less Traveled By
  200. 200 The Robot Invasion Has Come For Our Pool Halls
  201. 201 How Much Will It Cost To Sniff Out The Spies?
  202. 202 So You Want To Tether Your Goat. Now What?
  203. 203 So Your Archipelago Is Exploding. How Doomed Is Your Island?
  204. 204 Who Will Capture The Most James Bonds?
  205. 205 How Far Would You Go To Rig A Coin Flip?
  206. 206 The Riddler Just Had To Go And Reinvent Beer Pong
  207. 207 Alice And Bob Fall In Love
  208. 208 The Little, Mathematically Determined House On The Prairie
  209. 209 Can You Win Tic-Tac-Toe Blindfolded?
  210. 210 Santa Needs Some Help With Math
  211. 211 What The Heck Are These Dang Bits?
  212. 212 In Space, No One Can Hear Your 3D Printer Die
  213. 213 How Many Crossword Puzzles Can You Make?
  214. 214 Can You Escape A Maze Without Walls?
  215. 215 525,600 Minutes Of Math
  216. 216 Come On Down And Escape The Maze
  217. 217 Don’t Trust Anyone Older Than L
  218. 218 You’re Home Alone: Cigarette Cards And Bananagrams
  219. 219 How Many Numbers Contain The Numbers Of Their Numbers?
  220. 220 Can You Turn America’s Pastime Into A Game Of Yahtzee?
  221. 221 Tickets Old And New, And A Spelling Bee Where Order Hardly Matters
  222. 222 Free Drinks On Card Two
  223. 223 How Many Times A Day Is A Broken Clock Right?
  224. 224 How Many Earthlings Would Survive 63 Thanos Snaps?
  225. 225 Are You The Best Warlord?
  226. 226 Can The Riddler Bros. Beat Joe DiMaggio’s Hitting Streak?
  227. 227 How Many Soldiers Do You Need To Beat The Night King?
  228. 228 One Small Step For Man, One Giant Coin Flip For Mankind
  229. 229 Can You Win The Lotería?
  230. 230 You’ve Been Marooned By Kidnappers. Can You Escape At Dawn?
  231. 231 How Inefficient Can You Make Your Walk To Class?
  232. 232 I Would Walk 500 Miles And I Would Riddle 500 More
  233. 233 Can You Win The Superstring Scrabble Challenge?
  234. 234 What’s The Optimal Way To Play HORSE?
  235. 235 Can You Construct The Optimal Tournament?
  236. 236 Can You Escape This Enchanted Maze?
  237. 237 How Many Cars Are On This Circular Train?
  238. 238 Organize Some Debates! Maximize The Shade!
  239. 239 Which Billiard Ball Is Rigged?
  240. 240 Can You Fool The Bank With Your Counterfeit Bills?
  241. 241 What Are Your Chances Of Winning The U.S. Open?
  242. 242 Can You Help Dakota Jones Raid The Lost Arc?
  243. 243 Can You Win The Tour de FiveThirtyEight?
  244. 244 Which Baseball Team Will Win The Riddler Fall Classic?
  245. 245 Can You Escape The Enemy Submarines?
  246. 246 Can You Break The Riddler Bank?
  247. 247 Can You Carve The Perfect Pumpkin?
  248. 248 How Long Is The Snail’s Slimy Trail?
  249. 249 Can You Decode The Riddler Lottery?
  250. 250 How Fast Can You Skip To Your Favorite Song?
  251. 251 Can You Solve A Particularly Prismatic Puzzle?
  252. 252 How Many Pennies Should You Pinch?
  253. 253 Can You Roll The Perfect Bowl?
  254. 254 How Many More Palindrome Dates Will You See?
  255. 255 Can You Solve This Rather Pedestrian Puzzle?
  256. 256 Can You Flip Your Way To Victory?
  257. 257 Can You Get Another Haircut Already?
  258. 258 How Many Sets Of Cards Can You Find?
  259. 259 Can You Get The Gloves Out Of The Box?
  260. 260 Can You Catch The Free T-Shirt?
  261. 261 Can You Solve The Chess Mystery?
  262. 262 Can You Beat The GOAT Monty Hall Problem?
  263. 263 Can You Flip Your Way To Freedom?
  264. 264 Can You Eat An Apple Like A Toddler?
  265. 265 Can You Find The Fish In State Names?
  266. 266 Can You Join The World’s Biggest Zoom Call?
  267. 267 Can You Pinpoint The Planet?
  268. 268 How Long Will The Bacterial Colony Last?
  269. 269 Can You Connect The Dots?
  270. 270 Can You Stay In Your Lane?
  271. 271 Can You Make 24?
  272. 272 Can The Hare Beat The Tortoise?
  273. 273 Are You A Pinball Wizard?
  274. 274 Can You Cheat At Rock, Paper, Scissors?
  275. 275 Can You Reach The Beach?