There are six periods in each working day of the school. In how many ways can one arrange 5 subjects such that each subject is allowed at least one period?

Explanation

To solve the problem of arranging 5 subjects in 6 periods such that each subject is allowed at least one period, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Problem**: We have 5 subjects and 6 periods. Each subject must occupy at least one period. This means that one subject will occupy two periods, while the other four subjects will occupy one period each.

2. **Choosing the Subject to Repeat**: Since one subject will occupy two periods, we first need to choose which of the 5 subjects will be repeated. This can be done in \( \binom{5}{1} \) ways (choosing 1 subject from 5).

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