<span>Substitute for "a" and solve for "b":
7b = 10(b-24)
7b = 10b-240
3b = 240
b = 80 (# of calories in a banana)</span>
It's not clear where the paragraph break is between one and two, but I might be able to help you. The last option is incorrect, because all of the text relates which is why it's hard to determine where the paragraph break might be. Paragraph one does not offer a solution as it isn't until the end we know the cause of the dark day. While both paragraphs have at least one fact, paragraph one seemingly is full of guesses as to the cause of the dark day. This leaves the only correct option as the first one. The researchers decided to investigate the cause of the dark day, and then the results are reported.
