Two students from a group of eight boys and 12 girls are sent to represent the school in a parade.
if the students are chosen at random, what is the probability that the students chosen are not both girls?
a. 12/190
b. 33/95
c. 62/95
d. 178/190

Answer

c. 62/95

Explanation

Probability is the chance of an event happening.

Probability = (favorable outcome)/(total outcome)

P(girl) = 12/20 × 11/19

        = (12×11)/(20×19)

         = 132/380

         = 33/95

P( not a girl) = 1 - 33/95

                     = 62/95

see explanation

step-by-step explanation:

since the sequence is geometric there is a common ratio r between consecutive terms, that is

r = 4 ÷ - 2 = - 2

r = - 8 ÷ 4 = - 2

r = 16 ÷ 8 = - 2

the next term - 13 must be incorrect as it should be - 32 for the sequence to be geometric.

the first 4 terms are therefore geometric with common ratio r = - 2