Respuesta :

P= 1/2
Both 3 and 1 are factors of 21

Answer:

1/2

Step-by-step explanation:

There are 4 total choices.

The factors of 21 are 1,3,7, and 21

3 is included in the factors of 21

2 of the choices are listed

P (2 or a factor of 21) = number of choices included / total

                                    = 2/4

                                     =1/2