Problem 1: Multiples of 3 and 5
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.
A Solution
A simple approach to this problem is to
- initialize a counter variable to 0;
- iterate over the integers between 1 and 999 (inclusive): if the integer is a multiple of 3 or 5, add it to the counter.
The counter’s value is then the solution.
counter <- 0
for (i in 1:999) {
if (i %% 3 == 0 || i %% 5 == 0) {
counter <- counter + i
}
}
counter## [1] 233168