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Mary needs to read 3 books for her English class. Her teacher has given her a list of 7 books to choose from. How many different ways can she select the books?

35
65
45
55

Relax

Respuesta :

[tex] \frac{7!}{3!(7-3)!} = \frac{7*6*5*4*3*2*1}{3*2*1(4)!} =\frac{7*6*5*4*3*2*1}{3*2*1*4*3*2*1} [/tex]


[tex]= \frac{7*6*5}{3*2*1} = \frac{210}{6} =35[/tex]

The answer is A. 35

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