I skipped a bunch of questions and landed on this one. I’ll revisit the others… have no worries!

Problem 10:The sum of the primes below 10 is 2 + 3 + 5 + 7 = 17.

Find the sum of all the primes below two million.

How’d I solve it?

sumTotal = 0
#check if number is prime, return True / False
def is_prime(n):
if n > 1:
for i in range (2, n):
if (n % i) == 0:
return False
else:
return True
else:
return False
#loop to iterate through all numbers up to desired number
for x in range(2000000):
if is_prime(x):
sumTotal = sumTotal + x
print(sumTotal)

This surprisingly took a long time to solve on my Ubuntu server… which leads me to believe there must be a more efficient method. I’ll do some research, and I’ll be sure and share anything that I turn up.