For this one, fill in the numbers 1 through 9, using each only once, to make all of the vertical and horizontal equations correct. DARPA's math challenges: 23-DARPA: 2007 Millennium Prize Problems. What makes this difficult, and different from most hard math problems, is that it’s so unlike how we’re used to looking at numbers, especially in a sequence. Talwalker says teachers in Taiwan gave this problem to 9-year-olds, who understandably couldn't solve it—and neither could the teachers. So in the first column, you do 41 – 17 – 14 to get 10. The first Series is 2-3-4-5-... For instance, in the first pair, you multiply the 2 by two to get the 4 diagonally across from it, and the 3 to get the corresponding 6. T2 = D/30 Hence, the sum of the three digits is 11. SITUATION, #9 - Indian Scientist Magical Number Puzzle. AKBAR & BIRBAL    You can place weights on both side of weighing balance and you need to measure all weights between 1 and 1000. or 98*2*x + 3x ≡ -5 (mod 98) (You can also think of it as adding the second and third signs together than then subtracting that from the first sign.) Solve the problem in reverse way as below : ((√(8+8) × (3/3))! How can you make this equation accurate by using three of these four mathematical symbols: + – × ÷  (add, subtract, multiply, and divide)? For this math exercise, see how fast you can solve these not-so-hard math problems—while blasting your favorite music. Let x be the dollars of the check, and y be the cent. You may be able to find the same content in another format, or you may be able to find more information, at their web site. And no one could solve it—not even the teachers. You can use the main signs add, subtract multiply and divide. Sound off in the comments below. The last number that you entered (11) is n. They can be expressed as the sum of the cubes of two different sets of numbers. In the final column, you subtract 21 from 37, and then subtract 5 from that, to get the missing number of 11. Let's solve them together. Only Statements 1 and 3 are true. 98y = 199x + 5 4+5=4*[5+(4-1)]=32 Meghan Jones is a Staff Writer for RD.com who has been writing since before she could write. Grade 7 math word problems with answers are presented. D = 30 * T2 Solving for n, we obtain 11 as the answer and deduce that there were 12 people at the party. Below, you’ll see the binary notation for the decimal numbers 1 through 7. TRICK    But you’ll always have four digits, so until you have a four-digit number (1000), the digit(s) to the left of the highest place will be a zero. The required number is 236 and the sum is 11. 100y + x - 5 = 2(100x + y) 12 12 48 For this answer, you’ll quickly notice a pattern if you add up the digits in each time; ignore the decimal points. This one is tricky because it doesn’t tell you how many pins you need to knock over, so it could be any combination of the pins. But what stood out to me is that E is the last value on the first line and in the solution. So the number of open lockers is the number of perfect squares less than or equal to one thousand. 2D = Y(D/20 + D/30) Once you’ve solved this, brush up on some number facts you never knew before. There aren’t a lot of digits you multiply by that result in themselves again, which meant it’s almost definitely a 5. And if math isn’t your strong suit, take heart—most of these hard math problems just use very simple numbers with only basic operations—addition, subtraction, multiplication, and division. This fast-paced 3-D puzzle game involves a combination of quick thinking, logic, and luck to stack your spheres to earn the most points. so it loses 5 minutes every half-hour, They’ll challenge you to look at the “problems” a different way and test your logic and problem-solving skills while you’re solving. Expanding this out and rearranging, we find: