engineering mathematics MCQ #3969

The number of ways to choose 3 or more books from a shelf of 7 books is

engineering mathematics MCQ #3969

  1. Question 1

    Q1. The number of ways to choose 3 or more books from a shelf of 7 books is

    • A) 7C3 + 7C4 + 7C5 + 7C6 + 7C7
    • B) 2^7 - (7C0 + 7C1 + 7C2)
    • C) Both A and B
    • D) 7P3 + 7P4 + 7P5 + 7P6 + 7P7

    Answer: Both A and B

    Explanation: Both methods count the number of subsets with 3 or more elements: directly and by subtracting subsets with 0, 1, or 2 elements from total subsets.