Answer:
I don't know if you have ever watched Stranger Things, but this question makes me thing of one of the main characters in season 2: Bob Newbie... Lolz my fave....
anyways, if Bob had to pack 192 boxes but he had already packed 84 boxes in a time of 312 hours... (do you mean 3.12? because there is not 312 hours in a day...) let x be the length of time it takes to pack the remaining boxes. and create a formula like this: 192/84 = 3.12/x
to find x, cross multiply:
192x=84(3.12) = 262.08
Then isolate x
192/x = x
what you do to one side of the equation, do to the other, so divide 262.08/192=1.365
then depending on the situation, round 1.365 by whatever your assignment says to do.
"Easy peasy, right?" -Bob Newbie -Stranger Things 2 Sorry, i just had to do that reference...
So if i was correct on how to solve this, it should have taken Bob 1.365 hours to pack up the remaining boxes.
This is just how I would first think of solving this, but i'm no expert. all i can say is good luck. :)