At a school dance, 40% of the students had a date, 70% of the remaining students arrived at the dance with a group. What percentage of the students arrived alone?  Choose the correct option.
A) 40% of the students arrived alone.  B) 10% of the students arrived alone.  C) 42% of the students arrived alone.  D) 18% of the students arrived alone.  E) None of these.
Explanation:
Let total number of students be 100,
Then, number of students with a date = 40.
Number of students arriving with a group= 70% of 60 = 42.
Total number of students arriving alone = 100 – (40 + 42) = 18.
Thus, 18% of the students are arriving alone.
Answer: Option 18% of the students arrived alone..
<result>D</result>
At a school dance, 40% of the students had a date, 70% of the remaining students arrived at the dance with a group. What percentage of the students arrived alone?