Question

Difficulty: MediumVenn Diagrams and Set-Based Data

In a administrative evaluation conducted for 250250 government officers, data was collected regarding the completion of three specialized training modules: Cyber Security (CC), Data Analytics (DD), and Public Procurement (PP).

- 130130 officers completed Cyber Security
- 110110 officers completed Data Analytics
- 100100 officers completed Public Procurement
- 5555 officers completed both Cyber Security and Data Analytics
- 4040 officers completed both Data Analytics and Public Procurement
- 4545 officers completed both Cyber Security and Public Procurement
- 2020 officers completed all three modules

Based on the information provided, how many officers completed exactly two training modules?

  1. 8080Answer
  2. B
    140140
  3. C
    120120
  4. D
    100100

Answer

The number of officers who completed exactly two training modules is 8080.
To find the number of officers who completed exactly two modules, we isolate the three disjoint regions that represent taking two modules but not the third. Subtraction of the three-module intersection (2020) from each pair overlap yields: (5520)+(4020)+(4520)=35+20+25=80(55 - 20) + (40 - 20) + (45 - 20) = 35 + 20 + 25 = 80.

Step-by-Step Solution

1
Identify the given set values and intersections
N(C)=130N(C) = 130, N(D)=110N(D) = 110, N(P)=100N(P) = 100, N(CD)=55N(C \cap D) = 55, N(DP)=40N(D \cap P) = 40, N(CP)=45N(C \cap P) = 45, N(CDP)=20N(C \cap D \cap P) = 20
Extracting all cardinalities provided in the stem.
2
Calculate the number of officers in each exclusive two-set intersection region
Cyber & Data only =5520=35= 55 - 20 = 35; Data & Procurement only =4020=20= 40 - 20 = 20; Cyber & Procurement only =4520=25= 45 - 20 = 25
The intersection N(XY)N(X \cap Y) contains people taking all three modules as well. Subtracting N(CDP)N(C \cap D \cap P) isolates those taking ONLY two modules.
3
Sum the exclusive two-module regions
35+20+25=8035 + 20 + 25 = 80
Adding the three disjoint regions corresponding to exactly two training modules.

Key Concept

3-Set Venn Diagram Region Isolation and Inclusion-Exclusion
Estimated Time:1m 30s
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