Problem 7

What is the 10001st prime number?

Problem 6

Find the difference between the sum of the squares of the first one hundred natural numbers and the square of the sum.

Problem 5

What is the smallest positive number that is evenly divisible by all of the numbers from 1 to 20?

Problem 4

Find the largest palindrome made from the product of two 3-digit numbers.

Problem 3

What is the largest prime factor of the number 600851475143 ?

Problem 2

By considering the terms in the Fibonacci sequence whose values do not exceed four million, find the sum of the even-valued terms.

Problem 1

Find the sum of all the multiples of 3 or 5 below 1000.