Common Core HSS.CP.A.3 worksheet

Question 1

The probability it rains tomorrow is 0.7. If it rains, the probability the bus is late is 0.5. What is the probability that it rains and the bus is late?

Answer 

Question 2

Survey: Likes science & is in Club — 20; Likes science & not in Club — 14; Doesn't like science & in Club — 15; neither — 7. Given a student is in the Club, what is the probability they like science? Simplest form.

Answer (as a fraction)

Question 3

2% of people have a condition. A test is positive for 95% of people who have it and for 10% of people who don't. Someone tests positive. What is the probability they have the condition? Give 3 decimal places.

Answer 

Question 4

P(B) = 0.25 and P(A and B) = 0.0625. Find P(A | B).

Answer 

Question 5

30% of emails are spam. A filter flags 90% of spam emails and 5% of genuine emails. An email is flagged. What is the probability it is spam? Give 3 decimal places.

Answer 

Question 6

P(A) = 0.6, P(B) = 0.5 and P(A and B) = 0.3. Are A and B independent?

• A. Yes
• B. No

Question 7

Phone survey: Android: under 18 7, 18+ 8 iPhone: under 18 39, 18+ 36 A person aged 18+ is chosen at random. Find P(iPhone | 18+) as a fraction in simplest form.

Answer (as a fraction)

Question 8

The probability it rains tomorrow is 0.4. If it rains, the probability the bus is late is 0.8. What is the probability that it rains and the bus is late?

Answer 

Question 9

Survey: Likes science & is in Club — 6; Likes science & not in Club — 20; Doesn't like science & in Club — 15; neither — 9. Given a student is in the Club, what is the probability they like science? Simplest form.

Answer (as a fraction)

Question 10

1% of people have a condition. A test is positive for 95% of people who have it and for 2% of people who don't. Someone tests positive. What is the probability they have the condition? Give 3 decimal places.

Answer 

Question 11

P(B) = 0.25 and P(A and B) = 0.1. Find P(A | B).

Answer 

Question 12

20% of emails are spam. A filter flags 90% of spam emails and 10% of genuine emails. An email is flagged. What is the probability it is spam? Give 3 decimal places.

Answer 

Question 13

P(A) = 0.6, P(B) = 0.5 and P(A and B) = 0.3. Are A and B independent?

• A. Yes
• B. No

Question 14

Phone survey: Android: under 18 23, 18+ 34 iPhone: under 18 30, 18+ 32 A person aged 18+ is chosen at random. Find P(iPhone | 18+) as a fraction in simplest form.

Answer (as a fraction)

Question 15

The probability it rains tomorrow is 0.5. If it rains, the probability the bus is late is 0.5. What is the probability that it rains and the bus is late?

Answer 

Question 16

Survey: Likes science & is in Club — 17; Likes science & not in Club — 19; Doesn't like science & in Club — 10; neither — 11. Given a student is in the Club, what is the probability they like science? Simplest form.

Answer (as a fraction)