In a group of 5 students, some study French

Hi souvonik2k, you have answered the question correctly kudos to you.
This question is based on a basic logic ,
I will describe my logic here.
We do not know the number of students studying French or how many of them study German, so it is not possible to find the number of favorable events that one of the students is French student, and other is German student. But we can always say for sure that the number of favorable events will be a positive integer.
Now the total number of events will be 5C2 = 5!/(3!2!) = 10.
Hence required probability = positive integer/ 10
which always gives a single decimal or an integer. So from the options given, only C has a single decimal, other choices have two decimal.
Hence, Clearly, C is the answer.

This concept will be very useful for the complex probability questions, If we know that denominator is 10, then probability can not have 2 digit decimal answer, or so on. No need to calculate the number of cases which is a very tiresome process for some complex problems.



souvonik2k, Bunuel, VeritasPrepKarishma , Now tell me is the question a good one for GMAT?

(PS - I saw a concept video for probability by some GMAT prep, which inspires me to make this question.)

Please give kudos , if you like my post
I believe in learning by doing... I will be posting questions based on the basic concepts, but tricky though

Hi...

A Question should be solvable, it may be that the choices are helpful at times.
But if we are looking at a question that has no solution and is totally dependent on the choices, then the Question has a big question mark '?' on it.
When you say " what is the probability...?", It means the question has ONE answer, but in this case there could be different answers

Dear Sir
I agree with you, but in many GMAT questions, we get more than one answer and we do mark the options provided by the question.
I have edited the question by " what could be the probability "

Actually, my purpose of posting the question was to put emphasis on the concept, "This concept will be very useful for the complex probability questions, If we know that denominator is 10, then probability can not have 2 digit decimal answer, or so on. No need to calculate the number of cases which is a very tiresome process for some complex problems."


If you like my post, appreciate it by providing kudos...

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