Carousel
Math brain teasers require computations to solve.
Fred was in Washington, D.C., on a school trip to visit the Smithsonian. After lunch the teachers took the students to the Carousel on the Mall (this happened before they closed it down).
While Fred was enjoying his ride, he noticed that onethird of the number of his classmates riding ahead of him, plus threefourths of them riding behind him, equaled the total number of students on the carousel.
How many students were riding the carousel?
Answer
13.
The number of students ahead of him equals the number behind him. So,
1/3x + 3/4x = x + 1
When finding the common denominator for the lefthand side of the equation, we get 12, and the sum of the numerators then equals 13.
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Comments
darthforman
May 15, 2005


zonahobo
May 16, 2005
 I got to 13 figuring all could be considered ahead and behind but I expected you would have one student next to Fred or something as a trick .. so, glad it was straight math 
Cheerleader_09
May 26, 2005
 I thought it was pretty fun. 
Yoyobug02
Jun 08, 2005
 ummmmm thats wrong if u do 1/3 + 3/4 u have to change it to 4/12 + 9/12 and that equals 13/12 and that equals 1 and 1 /12 
Beaker
Jun 17, 2005
 x=12 using that equation 
paul726
Dec 08, 2005
 how do you assume the number ahead= the number behind? Except possibly that on a carousel, all people are ahead and all people are behind you. Poor wording in the teaser. 
phrebh
Dec 08, 2005
 You don't assume that the number ahead equals the number behind. You know it because a carousel is round. 
shadowwerss
Jul 03, 2006

I liked it pretty cool 
pating
Sep 11, 2007
 At first glance, I thought it was impossible to solve.
Clever idea for a carousel! 
javaguru
Feb 09, 2009
 Pretty cool. Gave me pause for a moment because I thought you weren't treating all in front as the same as all behind. Then I realized where the missing 1/12 was. 
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