摘要： 6、Sum square difference Hence the difference between the sum of the squares of the first ten natural numbers and the square of the sum is 3025 385 = 2 阅读全文

摘要： 1、Multiples of 3 and 5 If we list all the natural numbers below 10 that are multiples of 3 or 5, we get 3, 5, 6 and 9. The sum of these multiples is 2 阅读全文