mirror of
https://github.com/TheAlgorithms/Python.git
synced 2024-12-01 08:51:09 +00:00
15 lines
424 B
Python
15 lines
424 B
Python
|
'''
|
||
|
|
Problem Statement:
|
||
|
|
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 N.
|
||
|
|
'''
|
||
|
|
n = int(raw_input().strip())
|
||
|
|
sum = 0
|
||
|
|
terms = (n-1)/3
|
||
|
|
sum+= ((terms)*(6+(terms-1)*3))/2 #sum of an A.P.
|
||
|
|
terms = (n-1)/5
|
||
|
|
sum+= ((terms)*(10+(terms-1)*5))/2
|
||
|
|
terms = (n-1)/15
|
||
|
|
sum-= ((terms)*(30+(terms-1)*15))/2
|
||
|
|
print sum
|