in a class of 30 students there are 17 girls. two students are picked randomly to represent the class in the SRC. determine the probability

Question

in a class of 30 students there are 17 girls. two students are picked randomly to represent the class in the SRC. determine the probability that:
a. both students are boys
b. both students are girls
c. one of the students is a boy

in progress 0
Delilah 6 days 2021-09-10T21:54:20+00:00 1 Answer 0

Answers ( )

    0
    2021-09-10T21:55:21+00:00

    Answer:

    See below in bold,.

    Step-by-step explanation:

    There are 30-17 = 13 boys in the class.

    a.  Prob(First is a boy ) = 13/30 and Prob( second is a boy = 12/29).

    As these 2 events are independent:

    Prob( 2 boys being picked) = 13/30 * 12/29 =  26/145 or 0.179 to the nearest thousandth.

    b. By a similar method to a:

    Prob ( 2 girls being picked) =  17/30 * 16/29 = 136/435 = 0.313 to the nearest thousandth.

    c.  Prob (First student is a boy and second is a girl) =  13/30 * 17/29 = 221/870.

    Prob ( first student is a girl and second is a boy)  = 17/30 * 13/29 = 221/870

    These 2 events are not independent so they are added:

    Prob( one of the students is a boy)  = 2 (221/870 =  221/435 = 0.508 to the nearest thousandth.

Leave an answer

Browse
Browse

27:3+15-4x7+3-1=? ( )