530
It is pretty simple to figure this out, all you have to is find out how many words carl can type in 1 minute and you do that by dividing 318/3 and that would give you 106. So now that you know carl types 106 wpm, you just multiply 106 by 5 and that will give you 530.
So now you know that carl can type 530 words in 5 minutes, which is quite impressive.