Skip to content
Home › Geometry Math › Geometry Tests › Probability and Conditional Probability Test Answer Key with Scoring – Geometry

Probability and Conditional Probability Test Answer Key with Scoring – Geometry

← Back to the Probability And Conditional Probability test

Last updated: October 22, 2026 · Written by the Math Made Easy math teachers

Geometry Math Test Answer Keys – Mathbot, the Math Made Easy robot coach, with free printable test answer keys for Geometry

Looking for a probability and conditional probability test answer key? Then this answer key gives the solutions and the scoring guide of the Geometry test on Probability Rules, Conditioning and Fair Decisions. Each solution shows the rule, the numbers substituted and the final probability. The scoring notes show how partial credit is earned for the setup and for choosing the correct denominator.

Standards: S-CP.A.1, S-CP.A.2, S-CP.A.3, S-CP.A.4, S-CP.A.5, S-CP.B.6, S-CP.B.7, S-CP.B.8, S-CP.B.9, S-MD.B.6, S-MD.B.7 · Level: Grade 10 Geometry

Question 2 Venn Counts (3 points)

(a) 28 + 22 − 9 = 41, so 4160.

(b) 60 − 41 = 19, so 1960.

(c) 928 ≈ 0.321.

(a) 41/60 (b) 19/60 (c) 9/28

Scoring: 1 point per part.

Question 3 Two-Way Table (3 points)

(a) 95200 = 0.475.

(b) 73120 ≈ 0.608.

(c) 58105 ≈ 0.552.

(a) 0.475 (b) ≈ 0.608 (c) ≈ 0.552

Scoring: 1 point per part; award the point only if the denominator is the condition total.

Question 4 Independent or Not? (2 points)

P(A ∩ B) = 0.5 + 0.4 − 0.7 = 0.2.

0.5 · 0.4 = 0.2, equal to P(A ∩ B).

0.2; independent

Scoring: 1 point for the intersection, 1 point for the independence check.

Question 5 Orders and Groups (2 points)

(a) Order matters: 7 · 6 · 5 = 210.

(b) Order does not matter: ₇C₃ = 210 ÷ 6 = 35.

(a) 210 (b) 35

Scoring: 1 point each.

Question 6 Marbles Without Replacement (3 points)

6/15green5/14green9/14yellow9/15yellow6/14green8/14yellow
Two draws without replacement.

(a) 615 · 514 = 30210 = 17.

(b) Green then yellow: 615 · 914 = 54210. Yellow then green: 915 · 614 = 54210. Total 108210 = 1835.

(a) 1/7 (b) 18/35

Scoring: 1 point for (a), 2 points for (b).

Question 7 A Positive Test (3 points)

Sick and positive: 0.04 · 0.9 = 0.036. Healthy and positive: 0.96 · 0.1 = 0.096.

P(positive) = 0.132. P(sick | positive) = 0.0360.132 = 311 ≈ 0.273.

3/11 ≈ 27.3%

Scoring: 1 point for each of the two paths, 1 point for the conditional probability.

Question 8 Fair Spinner Game (2 points)

First game: each player wins with probability 24 = 12. Fair.

Second game: Ben wins with probability 14 and Anna with 34. Not fair.

First fair; second not fair

Scoring: 1 point for each game.