Problem 1

Problem: Find the sum of all numbers below 1000 which are a multiple of 3 or 5.

Solution: Given the numbers involved, we can simply brute-force the answer by simply checking each number below 1000 for divisibility by 3 or 5 and keep a running total.

max_number = 1000
total = 0

for x in range(0, max_number):
  if x % 3 == 0 or x % 5 == 0:
    total += x

print("Sum of all multiples of 3 or 5 below " + str(max_number) + ": " + str(total))