 In this video, we will provide the solution to question number 9 for practice exam number 3 for Math 1060, in which case a package is pushed across the floor, a distance of 52 feet, this is something like this, 52 feet. And this is accomplished by exerting a force of 15 pounds downward at an angle of 30 degrees. And this is with respect to the horizontal, so we're saying like this, with respect to the horizontal, this is 30 degrees. So how much work is done? Well, the formula we've learned previously is that the work is equal to the magnitude of the force times cosine of the angle between them times by the distance traveled here. So we have this information, we have 15 pounds of force, it was traveling or it moved 52 feet, and then this happened to be cosine of 30 degrees. We're going to have to do this without a calculator here. Cosine of 30 degrees, of course, is going to be root 3 over 2. So we have 15 times 52 times root 3 over 2. Right? You can of course divide 2 into 52, like so, square root of 3. Do a little bit of arithmetic. I mean, I confess that you don't have a calculator here, but it's not the worst arithmetic one could do. You know, we could multiply 2 digit numbers by scratch. And in the end, we're going to end up with 390 times the square root of 3 foot pounds, in which case then the correct answer we see is choice D.