Skip to lesson

Choose “Save as PDF” in the print dialog to keep a copy.

Cogito

AP Statistics · Chapter 2 · Lesson 1

Practice Worksheet

Probability Rules

Adding, multiplying, and knowing which.

11 problems · about 24 minutes · AP Statistics 4.4, 4.5, 4.6

NameDate

Figure — use these to answer the problems

Favourable outcomes against the rest.
favourable and the rest
all outcomes
Favourable3
The rest7
Figure 1

Warm Up

Straightforward practice. Get the method working first.

4 problems

  1. Independent, P(A) = 0.4, P(B) = 0.5. P(A and B)?

    Answer

  2. Independent, P(A) = 0.2, P(B) = 0.5. P(A and B)?

    Answer

  3. Mutually exclusive, P(A) = 0.3, P(B) = 0.4. P(A or B)?

    Answer

  4. Mutually exclusive events. What is P(A and B)?

    Answer

Build It Up

The same ideas with more to keep track of.

3 problems

  1. P(A) = 0.6. What is P(not A)?

    Answer

  2. P(B|A) = P(B). Independent? 1 for yes, 0 for no.

    Answer

  3. Are mutually exclusive events independent? 1 for yes, 0 for no.

    Answer

Stretch Yourself

Mixed problems. Work out what kind of question it is before you start.

4 problems

  1. Two fair coins. P(both heads)?

    Answer

  2. Select every statement that is always true.

    • Every probability lies between 0 and 1.
    • P(A or B) is always P(A) + P(B).
    • All outcomes together sum to 1.
    • Mutually exclusive means independent.
    • Tick every box that applies.

  3. Or

    P(A) = 0.3, P(B) = 0.5, P(A and B) = 0.1. What is P(A or B)?

    Answer

  4. And

    Independent events with P(A) = 0.5 and P(B) = 0.6. What is P(A and B)?

    Answer