Question

Difficulty: EasySets, Set Operations, and Venn Diagrams

In a technology conference of 6060 software developers, 3535 write code in Python, 2828 write in Java, and 1212 write in both Python and Java. How many developers write in neither of these two languages?

Answer: 9 developers

Answer

The number of developers who write in neither Python nor Java is 99.
The total number of developers writing in at least one language is given by 35+2812=5135 + 28 - 12 = 51. Subtracting this from the universal set size of 6060 gives 6051=960 - 51 = 9 developers who write in neither language.

Step-by-Step Solution

1
Calculate the number of developers who write in at least one of the languages.
n(PJ)=35+2812=51n(P \cup J) = 35 + 28 - 12 = 51
By the principle of inclusion-exclusion for two sets, n(PJ)=n(P)+n(J)n(PJ)n(P \cup J) = n(P) + n(J) - n(P \cap J).
2
Subtract from the universal set total to get the complement.
n((PJ))=6051=9n((P \cup J)') = 60 - 51 = 9
The number of elements outside the union is the universal set total minus the union cardinality.

Key Concept

Two-set inclusion-exclusion and complement cardinality
Estimated Time:1m 0s
Rate this question