If Amit's salary is 25% more than Sumit's salary, then the percentage by which Sumit's salary is less than Amit's salary is:

Steps to Solve

1. Assign a variable for Sumit's salary

Let Sumit's salary be represented by the variable $S$.

2. Calculate Amit's salary

Since Amit's salary is 25% more than Sumit's salary, we can express Amit's salary $A$ as:

$$ A = S + 0.25S = 1.25S $$

3. Determine the difference between the salaries

To find the difference between Amit's and Sumit's salaries, we subtract Sumit's salary from Amit's salary:

$$ \text{Difference} = A - S = 1.25S - S = 0.25S $$

4. Calculate the percentage difference

Now, we want to find by what percentage Sumit's salary is less than Amit's salary. The formula for percentage difference is:

$$ \text{Percentage Difference} = \left( \frac{\text{Difference}}{A} \right) \times 100 $$

Substituting the values we found:

$$ \text{Percentage Difference} = \left( \frac{0.25S}{1.25S} \right) \times 100 $$

5. Simplify the percentage difference calculation

We can simplify:

$$ \text{Percentage Difference} = \left( \frac{0.25}{1.25} \right) \times 100 = 0.2 \times 100 = 20% $$