Project Eular #1
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 23.
Find the sum of all the multiples of 3 or 5 below 1000.
#!/usr/bin/env python
sum = 0
for num in range(3,1000,3):
sum ＝ sum+num
for num in range(5,1000,5):
sum = sum+num
for num in range(15,1000,15):
sum = sum-num
print sum