Project Euler Forum

Okay I'm confused and it seems over 10,000 people weren't so any input would be appreciated.

Problem 20 states to find the "sum of the digits in 100", which would seem to be 1+0+0 = 1. This isn't right. The example shows n! = ... so I tried putting in the answer for 100!, but the answer box doesn't provide CLOSE to enough digits. And besides, that's products, not sum. So I tried doing a factorial but with addition instead of multiplication, but that didn't work either.

I'm obviously missing something. A hint in the correct direction would be wonderful.

Thanks,
D

PS - This is my second or third day on Project Euler and I'm hooked!

If you take 10! you get 3628800 and the sum of the digits is 3+6+2+8+8+0+0 = 27.
That clear it up for you?

Yes, thanks!!

(I know, im grave digging a bit sorry)

i think it should be changed, as it lead to my confusion also, perhaps add that snippet that elendia posted could be added onto the discription?

That is a perfectly reasonable suggestion. In fact, I was surprised that I had not put an example with that problem as that is the standard "formula" for the problems. Anyway, I've added the good example which elendiastarman gave.
Problem 20 (View Problem)