# Problem 12

To save you going all the way to Project Euler to read it, I have copied problem 12 here for your puzzle solving convenience…

The sequence of triangle numbers is generated by adding the natural numbers. So the 7

^{th}triangle number would be 1 + 2 + 3 + 4 + 5 + 6 + 7 = 28.The first ten terms would be:

1, 3, 6, 10, 15, 21, 28, 36, 45, 55, …

Let us list the factors of the first seven triangle numbers:

1: 1

3: 1,3

6: 1,2,3,6

10: 1,2,5,10

15: 1,3,5,15

21: 1,3,7,21

28: 1,2,4,7,14,28We can see that 28 is the first triangle number to have over five divisors.

What is the value of the first triangle number to have over five hundred divisors?

In case you were wondering, the answer to problem 10 is

```
primes = Primes.new
puts primes.find_primes_less_than(2000000).inject{|s,n| s+n}
```

How come *inject* and *collect* haven’t caught on in other languages? They are awesome.