Step-by-step explanation: What I like doing with problems like this is work backward, so that is how this explanation is going to work.
830*0.40=332 so that is how I got 40% now lets dig a little deeper.
How to find percent is take the whole and times it by the decimal of percent you want (eg. if 400 is my whole I want to find out what 30% of it is I would do 400*0.30)
So then we take our 830 times it by what we think best fits and that's how I solved it!