A physical education class has 21 boys and 9 girls. Each day, the teacher randomly selects a team captain. Assume that no student is absent. What is the probability that the team captain is a girl two days in a row?

0.09

Step-by-step explanation:

From the question, in a physical education class, there are 21 boys and 9 girls. Each day, the teacher randomly selects a team captain randomly.

The probability that the team captain will be a girl two days in a row assuming no student is absent will be:

Boys = 21

Girls = 9

Total = 21 + 9 = 30

P(pick a girl) = 9/30 = 3/10 = 0.3

P(pick a girl 2 days in a row) = (0.3)²

= 0.09

d

step-by-step explanation:

the solution is in the picture

option a, c,d are correct.

step-by-step explanation:

from the given figure, it is given that z is equidistant from the sides of the triangle rst, then from triangle tzb and triangle szb, we have

tz=sz(given)

bz=zb(common)

therefore, by rhs rule,δtzb ≅δszb

by cpctc, sz≅tz

also, from δctz and δasz,

tz=sz(given)

∠tcz=∠saz(90°)

by rhs rule, δctz ≅ δasz, therefore by cpctc, ∠ctz≅∠asz

also,from δasz and δzsb,

zs=sz(common)

∠zbs=∠saz=90°

by rhs rule, δasz ≅δzsb, therefore, by cpctc, ∠asz≅∠zsb

hence, option a, c,d are correct.