This is a multiple choice question in one of tests I just wrote and I did not know the answer to it. I was just stuck on this during the test. It is a very weird question, one I find to be impossible.
Here it goes:
Scientists have determined some species of birds tend to avoid flights over large bodies of water during daylight hours. It is believed that more energy is required to fly over water than land because air rises over land and falls over water during day. A bird with these tendencies is released from an island that is 5 km form the nearest point B on a straight shoreline, flies to point C on the shoreline, and then flies along the shoreline to its nesting area D. Assume that the brid instinctively chooses a path that will minimize its energy expenditure. Points B and D are 13 km apart.
If it takes 2 times as much energy to fly over water as land, what is the minimum amount of total energy that the bird could expend returning to its nesting area?
a) 2.88 units $\phantom{abcd}$ b) 21.66 units $\phantom{abcd}$ c) 23.00 units $\phantom{abcd}$ d) 27.85 units
I have no idea how to do this question because it makes absolutely no sense to me. I have sat and thought but I just am not getting anywhere.