Mathematics for IGCSE & O level - Sets (Section 3 - No. 1)
How many students study at least one subject in this scenario: 25 students study history, 20 study geography, and 10 study both?
35
45
55
15
ব্যাখ্যা
Use the principle of inclusion-exclusion: 25 + 20 - 10 = 35.