There are m copies each ofn different books in a university library. The number of ways in which one or more than one book can be selected is

Options

A. `m^(n)+1`
B. `(m+1)^(n)-1`
C. `(m+1)^(n)-m`
D. `m^(n)`

Answer

To solve the problem of finding the number of ways to select one or more books from m copies of n different books, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Selection Options**:
- For each of the n different books, we have m copies available.
- For each book, we can select 0, 1, 2, ..., up to m copies.

2. **Calculating Choices for One Book**:
- For each book, the number of ways to select copies is (m + 1). This includes the option of selecting 0 copies, which is why we add 1.

3. **Total Choices for All Books**:
- Since there are n different books and each book can be chosen in (m + 1) ways, the total number of ways to select books (including the option of selecting none) is:
\[ (m + 1)^n \]

4. **Excluding the Case of Selecting No Books**:
- The problem asks for the number of ways to select one or more books. Therefore, we need to exclude the case where no books are selected.
- The number of ways to select at least one book is:
\[ (m + 1)^n - 1 \]

5. **Final Answer**:
- Thus, the final expression for the number of ways to select one or more books is:
\[ (m + 1)^n - 1 \]