Project Euler Problem 10: Summation of primes

Summation of primes   Problem 10 The sum of the primes below 10 is 2 + 3 + 5 + 7 = 17. Find the sum of all the primes…

Project Euler Problem 9: Special Pythagorean triplet

Special Pythagorean triplet Problem 9 A Pythagorean triplet is a set of three natural numbers, a < b < c, for which, a2 + b2 = c2 For example, 32 + 42 = 9 + 16 = 25 = 52. There…

Project Euler Problem 8: Largest product in a series

Largest product in a series Problem 8 The four adjacent digits in the 1000-digit number that have the greatest product are 9 × 9 × 8 × 9 = 5832….

Project Euler Problem 7: 10001st prime

10001st prime Problem 7 By listing the first six prime numbers: 2, 3, 5, 7, 11, and 13, we can see that the 6th prime is 13. What is the…

Project Euler Problem 6: Sum square difference

Sum square difference Problem 6 The sum of the squares of the first ten natural numbers is, 12 + 22 + … + 102 = 385 The square of the sum of the…

Project Euler Problem 5: Smallest multiple

Smallest multiple Problem 5 2520 is the smallest number that can be divided by each of the numbers from 1 to 10 without any remainder. What is the smallest positive…

Project Euler Problem 4: Largest palindrome product

Largest palindrome product Problem 4 A palindromic number reads the same both ways. The largest palindrome made from the product of two 2-digit numbers is 9009 = 91 × 99….

Project Euler Problem 3: Largest prime factor

Largest prime factor Problem The prime factors of 13195 are 5, 7, 13 and 29. What is the largest prime factor of the number 600851475143 ? By the fundamental theorem…

Project Euler Problem 2: Even Fibonacci numbers

Even Fibonacci numbers Problem Each new term in the Fibonacci sequence is generated by adding the previous two terms. By starting with 1 and 2, the first 10 terms will…

Project Euler Problem 1: Multiples of 3 and 5

Multiples of 3 and 5 Problem If we list all the natural numbers below 10 that are multiples of 3 or 5, we get 3, 5, 6 and 9. The…