Nine Digit NumberPro Problems > Math > Number and Quantity > Number Theory
Nine Digit Number
Without the use of a calculator, find a nine-digit number which is one less than a perfect cube, and which is a multiple of 640,801.
SolutionIn order to make it feasible for teachers to use these problems in their classwork, no solutions are publicly visible, so students cannot simply look up the answers. If you would like to view the solutions to these problems, you must have a Virtual Classroom subscription.
In how many zeroes does the number (220)(315)(43)(540)(711) end?
I wrote out all the integers from 1 to 20 inclusive (inclusive means including both 1 and 20). Then I crossed out all the even numbers, all the multiples of five, and all the perfect squares. How many numbers were left?
Baby Bart builds a pyramid with blocks. The top level of his pyramid is made up of 1 block. The next level down is two blocks wide and two blocks long. If each successive level has one more block in width and in length than the level above it, and the pyramid is 25 levels tall, how many blocks are used?