There are `100` students in a hostel. Food provision for them is for `20` days. How long will these provisions last, if `25` more students join the group?

Explanation

To solve the problem step by step, we can use the concept of inverse proportions. Here's how we can approach it:

### Step 1: Understand the relationship
We know that the number of students and the number of days the food lasts are inversely proportional. This means that as the number of students increases, the number of days the food lasts decreases.

### Step 2: Set up the initial condition
Initially, there are 100 students and the food lasts for 20 days. We can represent this as:
- Number of students (S1) = 100
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