<human>: I understand that it calculates on some sort of guessing system, but here's what I don't understand. According to Micro$hit's website, it only makes 20 guesses and then gives up. TWENTY!!! First of all, it uses 6 threads and 83.06 megs of ram, if that's not enough for properly calculating something like the program is supposed to, then why don't they up that? I understand that they don't want to make the program too bulky, but seriously, every time I use the IRR command (which I wouldn't be doing in the first place if it wasn't for this stupid homework assignment), I have to keep putting in random values till it figures it out. If I have to do the work myself, then why is that command even there? It's supposed to to the fucking work for me!

Sorry that this turned into sort of a rant, but this shit is seriously pissing me off...

Can you summarize the given text in a few sentences?
<bot>: Excel uses 6 threads and 83.06 megabytes of ram, so why does it only make 20 guesses at calculating the IRR, when that just makes me have to do all the work myself?