Back to Understand conditional probability — Problem 3 · Task Set 20
Exercises: Understand the Conditional Probability of A Given B as P(A and B)/P(B)
Work through each section in order. Show your reasoning where indicated. For explanation problems, write in complete sentences. Express probabilities as fractions in lowest terms or as decimals where requested.
Grade 10·20 problems·~35 min·Common Core Math - HS Statistics and Probability·group·hss-cp-a-3
Work through problems with immediate feedback
A
Fluency Practice
Compute each conditional probability. Two-way tables give counts.
1.
A survey of 200 people recorded coffee and tea drinking.
| Drinks Coffee | No Coffee | Total | |
|---|---|---|---|
| Drinks Tea | 40 | 30 | 70 |
| No Tea | 80 | 50 | 130 |
| Total | 120 | 80 | 200 |
Compute . Express your answer as a fraction in lowest terms.