Math Brain Teasers

All 20 Math Brain Teasers

• #1 For problems 1 & 2, you are given four 'squares' of numbers for each problem. The same mathematical function(s) are applied to each square in each problem, but problems 1 & 2 each ...
• #2 2 7 0 3 0 11 2 ? 8 9 5 6 10 11 4 3
• #3 12 members were present at a board meeting. Each member shook hands with all of the other members before & after the meeting. How many hand shakes were there?
• #4 At Probability University, there are 375 freshmen, 293 sophomores, 187 juniors, & 126 seniors. One student will randomly be chosen to receive an award. What percent chance is there...
• #5 If you take a marker & start from a corner on a cube, what is the maximum number of edges you can trace across if you never trace across the same edge twice, never remove the marke...
• #6 A cube is made of a white material, but the exterior is painted black. If the cube is cut into 125 smaller cubes of exactly the same size, how many of the cubes will have 2 of thei...
• #7 If you started a business in which you earned $1 on the first day, $3 on the second day, $5 on the third day, $7 on the fourth day, & so on, how much would you have earned with thi...
• #8 A worker earns a 5% raise. A year later, the worker receives a 2.5% cut in pay, & now her salary is $22702.68. What was her salary to begin with?
• #9 Two trains, each two miles long, enter two one mile long tunnels that are two miles apart from one another on the same track. The trains enter the tunnels at exactly the same time....
• #10 If the same functions are applied to reach the results in each of the three sets of numbers, find what number should replace the ? in the last set: 21 5 28 13 16 2 24 30 ? 17 7 25 ...
• #11 You have 1,432 feet of fence that must be strung out in a straight line. A fence post must be placed for every 4 feet of fence, so how many fence posts will be needed?
• #12 If each letter in the following equations represents a number from 1 through 9, determine what number each letter represents. A. A+A+B+C = 13 B. A+B+C+D = 14 C. B+B+C+D = 13
• #13 Anyone telesent (like being teleported or "beamed up") to Space Station Exray will arrive in pod A, B, or C. You are twice as likely to arrive in pod A than in pod B, & three times...
• #14 In a perfectly circular arena, I walk from the edge directly to the center. I then turn directly to my left, & walk in a straight line to the edge of the arena. I then turn to the ...
• #15 If 7 web programmers can format 1001 puzzles in 429 minutes, how long does it take 3 web programmers to format those 1001 puzzles?
• #16 If you have 3 dice that are shaped as a tetrahedron, a cube, & an icosahedron, & you rolled each of them, each die would display a number from 1-4, 1-6, & 1-20, respectively. Assum...
• #17 What are the maximum of separate volumes that can be formed by 2 interpenetrating cubes? a) Use only the surfaces of the cubes for consideration of the bounded volumes. b) Do not c...
• #18 Andy, Bart, and Chris are eating at Smiley's All You Can Eat Pizza Buffet. Andy made 2.4 times as many trips to the buffet as Bart, and Bart made 6 fewer trips than Chris. What is ...
• #19 In training for a competition, you find that swimming downstream (with the current) in a river, you can swim 2 miles in 40 minutes, & upstream (against the current), you can swim 2...
• #20 All of the students at a college are majoring in psychology, business, or both. 73% of the students are psychology majors, & 62% are business majors. If there are 200 students, how...