Testing students

Giving a test to a group of students, the grades and gender are summarized below.
Grades and Gender

	A	B	C	Total
Male	20	6	19	45
Female	17	18	13	48
Total	37	24	32	93

If one student is chosen at random,

a) Find the probability that the student got a B.

b) Find the probability that the student was female AND got a "C":

c) Find the probability that the student was female OR got a "B":

d) If one student is chosen at random, find the probability that the student got a 'B' GIVEN they are male

Correct answer:

a =  0.2581
b =  0.1398
c =  0.7204
d =  0.1333

Step-by-step explanation:

$a=\frac{24}{93}=0.2581$

$b=\frac{13}{93}=0.1398$

$c=\frac{48+32-13}{93}=0.7204$

$d=\frac{6}{45}=0.1333$

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