Question

$40$% of all high school students hate roller coasters; the rest love them. $20$% of those students who love roller coasters own chinchillas. What percentage of students love roller coasters but do not own a chinchilla?

• A. $45$
• B. $30$
• C. $50$
• D. $48$

Answer 1

Answer: (D)

$48$

Since all the numbers in this problem are given in percentages, assign a grand total of $100$ students. You know that $40$% of all high school students hate roller coasters, so fill in $40$ for this total and $60$ for the number of students who love roller coasters. You also know that $20$% of those students who love roller coasters own chinchillas. It does not say that $20$% of all students own chinchillas. Since $60$% of students love roller coasters, $20$% of $60$% own chinchillas. Therefore, fill in $12$ for the students who both love roller coasters and own chinchillas. The other $48$ roller coaster lovers do not own chinchillas.

	Love RCs	Do Not	Total
Chinchilla	$12$
No Chinch.	$48$
Total	$60$	$40$	$100$