How Many Students Got an A?
Math brain teasers require computations to solve.
The teacher has finished grading the math papers at West High School. The class size is under 30. One third of the class got a `B`, one fourth got a `B` and one sixth got a `C`. One eighth of the class flunked and the remainder of the class received an `A`.
How many students in the class received an `A`?
Answer
Find a common denominator for 3, 4, 6 and 8. The only common denominator smaller than 30 is 24. Therefore, the class size was 24 and the grades were:
B: 8
B: 6
C: 4
D/F: 3
The number of students who received A`s was 3 (24  21)
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Comments
dewtell
Jul 26, 2002
 So the only possible grades at this school
are A, B, B, C, and F? No B+, A, C+, etc.?

Rowsdower
Dec 24, 2003
 Just because no one received a certain grade doesn't mean they couldn't. 
thebuddhawithin
Jul 04, 2004
 Wow, I haven't used common denometers in years! I totally forgot! 
canu
Jul 13, 2004
 The comment by dewtell is most apt.
 The correct answer to the teaser as stated is: "No more than 3."
 For the correct answer to be: "3", the question should be changed to something like:
"The other students in the class received an A; how many were they?" 
stephiesd
Dec 15, 2005
 Yay!! not only did i get it, but i did it in my head. Yay for fraction review. (even though i hate them to death) 
smiley_lover
Mar 07, 2006
 I GOT IT!!! In my head too! This is the first one i did in my head.......RIGHT!!!!!! 
TehIgnored
Mar 09, 2006
 Just because 24 would be a common denominator, does not mean that's the number of kids in the class.....i dislike these teasers that leave out vital information, and then only offer up one answer based on a piece of information of the authors choosing, and I don't think they should be posted...
I say there's 27 kids in the class, and nothing in the teaser says I can't.... 
Crazycriely
Apr 22, 2006
 ummm In my school a D isnt failing...so that kinda threw me off 
triskit
Apr 22, 2006
 yeah same here. Actually D is never failing. 
spazzyjazzy93
May 27, 2006
 i did that in my head too! yay!
i dont get CANU's comment at all 
eyenowhour
Dec 19, 2006
 If you get a score equivalent to a D in a pass/fail class, you would fail the class. However, if you were taking the class for a letter grade, you would pass the class with a D. I don't know why this is. 
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