A certain reaction is of first order . After 30 secoonds , `50` % of the reactant ramains .
How long would it require for 25% of the reactant to be decomposed ?

Explanation

To solve the problem step by step, we will use the properties of first-order reactions and the relationship between the half-life and the time taken for a certain percentage of reactant decomposition.

### Step 1: Understand the given information
We know that the reaction is of first order and that after 30 seconds, 50% of the reactant remains. This means that 50% of the reactant has decomposed in that time.

### Step 2: Identify the half-life (T_half)
The time taken for 50% of the reactant to decompose is known as the half-life (T_half). From the problem, we have:
- T_half = 30 seconds
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