It's written a little oddly, but makes sense. I can show you how to do it in Excel, but since you want to understand it first, the best way to start...
I've seen this problem before, given to students at this level, probably intended to be solved by orderly trial and error, with a little intelligence...
Let's combine these ideas. Add to your picture the segment XY through P perpendicular to AP, to make an isosceles triangle AXY. You want to show that...
The real issue is not whether they "make" an angle, but how that angle is related to the vectors. Depending on how the vectors are related and where...
I wrote that a little too quickly, without time to check the problem. Your sum is 9, not 8. Having 4 bins with 9 balls, if you allowed 0 in any, you...
When they say it "weighs 1.7 kg", they just mean that weighs as much (under the same conditions) as a mass of 1.7 kg; in other words, its mass is 1.7...
I was a software engineer for many years, and have been teaching at a community college since 2004. Since 1998, I was a part of Ask Doctor Math (http://mathforum.org/dr.math/ and now http://themathdoctors.org/).