If A's salary is 30% more than B's salary, then by what percentage is B's salary less than that of A? (correct to one decimal place)

Answer: Option B

Given:
Salary of A is 30% more than salary of B
Calculation:
Let the salary of B be 100x
Salary of A = 100x + 100x × 30%
⇒ 130x
Percentage difference = $$\frac{130\text{x}-100\text{x}}{130\text{x}}\times 100$$
= $$\frac{30\text{x}}{130\text{x}}\times 100$$
= 23.07% ≈ 23.1%
∴ B's salary is 23.1% less than that of A.