.'.'. i will give medal .'.'.
There are 30 students in a class.
20 study physics 15 study chemistry and 3 study neither physics nor chemistry.
(i) A student is chose at random. Find the probability that the student studies Physics but not chemistry.
(ii) A student who studies physics is chosen at random. Find the probability that this student does not study chemistry.

Question

.'.'. i will give medal .'.'.
There are 30 students in a class.
20 study physics 15 study chemistry and 3 study neither physics nor chemistry.
(i) A student is chose at random. Find the probability that the student studies Physics but not chemistry.
(ii) A student who studies physics is chosen at random. Find the probability that this student does not study chemistry.

anonymous · Answer

For the first one you need two conditions to happens at once. 
A, Student studies Physics
B, Student does not study Chemistry. 

Can you find P(A) and P(B)?

anonymous · Answer

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