Computer question from Social Forest Worker exam, 2026 by JKSSB
In a software firm of 200 developers, everyone knows at least one language: Python (P), Java (J), and C++. The number of developers who know only Python is equal to the number of developers who know only Java. 30 developers know only C++. Exactly 10 developers know all three languages. 35 developers know both Python and Java, 25 know both Java and C++, and 30 know both Python and C++. What is the total number of developers who know Python?
Last updated Jul 21, 2026
Correct Answer:
Option C —
105
Step -by-Step Breakdown
1. Break Down the Known Regions
Developers who know all three languages: 10
Developers who know both Python and Java: 35
Subtracting the ten who know all three leaves 25 who know only Python and Java.
Developers who know both Java and C++: 25
Subtracting the ten who know all three leaves 15 who know only Java and C++.
Developers who know both Python and C++: 30
Subtracting the ten who know all three leaves 20 who know only Python and C++.
Developers who know only C++: 30
2. Find the Number of Developers Who Know Only Python
Combining all known exclusive groups gives:
Thirty (only C++) plus twenty-five (only Python and Java) plus fifteen (only Java and C++) plus twenty (only Python and C++) plus ten (all three languages).
This totals 100 developers in these specific combined groups.
Since all two hundred developers know at least one language:
Subtracting one hundred from two hundred leaves 100 developers remaining.
These remaining one hundred developers are split equally between those who know only Python and those who know only Java.
Dividing one hundred by two gives 50 developers who know only Python (and 50 who know only Java).
3. Calculate Total Python Developers
To find the total number of developers who know Python, sum all groups that include Python:
Developers who know only Python: 50
Developers who know only Python and Java: 25
Developers who know only Python and C++: 20
Developers who know all three languages: 10
Fifty plus twenty-five plus twenty plus ten equals 105.
Answer verified by Quintessence Classes faculty — Karan Nagar, Srinagar.
