# For an exam, there are 28 terms to study, there will be 6 on the exam and I have to answer 4...?

How many terms do I have to study to guarantee four of them will be on the exam?

Thanks.

Relevance
• Barolb
Lv 5
8 years ago

Well, to guarantee that you'll get 100%, then study all of them, but if you want the mathematical answer, then it will be the following:

28 Choose 6: There are 376740 different combinations of terms that could be used.

Of those 6, there would be 4 chosen, so the result would be 6 choose 4, so your final answer is 15.

In all seriousness, it really all depends. if your teacher stressed some of those terms as being important, then they are likely to be on the exam more so than not as important terms noted; however, that does not decrease the chances of those terms even showing up on the exam. That is why your safest bet is to review all 28 terms to ensure a higher chance of getting 6 terms, and 4 of which that you know. Whatever you reviewed in class will also prove to be a hint, so if any terms were noted during the review, make sure to pay attention (or paid attention) to them, and make note of them, as there is a chance that they will be on your exam.