A class contains 10 sophomores, 15 juniors, and 20 seniors. A committee of 5 students is to be chosen. Each student is equally likely to be selected to serve on the committee. Let A be the event exactly 3 juniors are selected to serve on the committee. Let B be the event exactly 2 seniors are selected to serve on the committee. Required:
a. Find P(A)
b. Find P(A| B)

P(A) = 0.1620 , P(A|B) = 0.0707

Step-by-step explanation:

Total people = 10 + 15 + 20 = 45 , Sophomores = 10, Juniors = 15 , Seniors = 20

P(A) , exactly 3 juniors selected = (15 c 3) (30 c 2) / (45 c 5) = (455 x 435) / 1221759 = 0.1620  

P (B) , exactly 2 seniors selected = (20 c 2) (25 c 3) / (45 c 5) = (190 x 2300)/ 1221759 = 0.3576

P(A|B), exactly 3 juniors & exactly 2 seniors selected = P (A∩B) / P (B)

(15 c 3) (20 c 2) / (45 c 5) = (455 x 190) / 1221759 = 0.0707

1. 22

2. 1

3. 7

4. 18

step-by-step explanation

e2020 got it right

d. millimeters per hour.

step-by-step explanation:

we are given that,

carlo used a rain gauge to measure the amount of water his lawn is receiving from the sprinklers.

since, according to the options, we see that,

water cannot be measured by 'miles per hour', 'meters per second' and 'grams per seconds'.

we get that, the water can be measured by 'millimeters per hour'.

hence, the appropriate rate for describing the amount of water is 'millimeters per hour'.