<ol>
<li>A class has twice as many boys as girls. The students in the class stand in one line, with a girl at the front of the line. Which of the following must be true?
A. The last person in line is a girl.
B. the last person in line is a boy
C. There are more girls than boys in the class
D. There are at least two girls standing to each other.
E. There are at least two boys standing next to each other.
I didn't understand this question, can somebody help?? And the answer is E.</li>
</ol>
<p>There is no math involved. The students are standing in a line like this: GBBGBB</p>
<p>Clearly A, B, and C are not true.
That leaves D and E.</p>
<p>Can you think of counterexamples to D?
Yes, the simplest is G-B-B.</p>
<p>That leaves E.
What is E really saying? You know there are more boys than girls. If you had equal boys and girls, you could make a line like this: G-B-G-B-G-B. But since you have more boys, you have to squeeze them in the line somewhere. Anywhere you put them, they are next to another boy.</p>
<p>I don’t understand skieurope’s solution. That only eliminates A, C and D, and doesn’t give an argument for B or E. However B is eliminated due to the counterexample GBBBBG.</p>
<p>^^You don’t understand skieurope’s explanation because it is erroneous (as you probably realize)</p>
<p>Actually it is pretty self explanatory after all, however that guy who tried to explain knows the answer but doesn’t really know how to convey the idea </p>