
Mind Your Decisions Blog
1,024 FOLLOWERS
Mind Your Decisions blog shares Math Videos, Math Puzzles, Game Theory by Presh Talwalkar.
Mind Your Decisions Blog
1d ago
0:00 problem 1:30 attempt 2:25 solution 5:22 part 2 6:58 lucky 9:00 logic This riddle has been asked as an interview question at many companies, including Apple. In front of you are 3 boxes. One box contains only apples, another box contains only oranges, and the last contains both apples and oranges. Currently the first ..read more
Mind Your Decisions Blog
1w ago
How many of these puzzles can you solve? Puzzle 1 Puzzle 2 Puzzle 3 The coin on the left is rolled, without slipping, halfway around the coin on the right. Will the coin be upside down? Puzzle 4 Puzzle 5 Puzzle 6 Puzzle 7 As usual, watch the video for solutions. 7 Creative Puzzles 0:00 ..read more
Mind Your Decisions Blog
1w ago
I came across a homework problem described as “scary” on Reddit AskMath. You need to fill in the number sentences using the numbers 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 exactly once. You should try a few possibilities to see why this is a challenging question. And do not waste too much ..read more
Mind Your Decisions Blog
1w ago
These are two fun problems I saw on Reddit AskMath. Problem 1 A circle of radius 12 is inscribed in a right triangle, dividing the hypotenuse into lengths of a and b = 44. What is the length of a? Problem 2 A right trapezoid has parallel sides of 3 and 7. What is the ..read more
Mind Your Decisions Blog
2w ago
Thanks to Daneesha for the suggestion! This question from Sri Lanka’s 2021 G.C.E A/L Combined Maths exam paper had an error that the test makers overlooked! The figure below consists of a rectangle and two attached circular sectors. All length dimensions are in meters. The area of the entire shape is 36 m2. Show the ..read more
Mind Your Decisions Blog
2w ago
This is a fun Cambridge entrance exam question (UCLES STEP Mathematics I, 2009, Q1). A proper factor of an integer N is a positive number that divides N but is not equal to 1 or N. (A) Show that 32×53 has exactly 10 proper factors. (B) How many other integers of the form 3m×5n have ..read more
Mind Your Decisions Blog
2w ago
I present a video to show how you can use your fingers to: –multiply numbers from 6 to 9 –multiply numbers from 11 to 15 –remember the times table for 9 Finger Multiplication 3 Tricks 0:00 intro 0:23 multiply 6 to 9 7:18 why works 6 to 9 11:52 multiply 11 to 15 15:40 why ..read more
Mind Your Decisions Blog
2w ago
Note to long-time readers: Puzzle 1 is a new problem. Puzzles 2 and 3 are re-posts added to this compilation. (YouTube is preferring longer videos, and it is a good time to re-share overlooked problems.) Puzzle 1 This is adapted from a 6th grade cram school problem in China. A solid figure is made by ..read more
Mind Your Decisions Blog
3w ago
This is a fun problem that comes from a math competition. The two circles with radii r and s have common tangents of AB and PQ. The length of PQ is 14 units and the length of AB is 16 units. What is the value of rs ? As usual, watch the video for a ..read more
Mind Your Decisions Blog
3w ago
The SAT in America is a standardized test used for admission to college. Today the test focuses on the two areas Reading & Writing and Math. The very first test had 10 sections covering a range of questions. How well would you do on the test? The video includes a sample of the 390 questions ..read more