Salary of Ram is 20 percent more than Shyam's. By what percent is Shyam's salary less than Ram.

Correct option is B

Given:
Salary of Ram is 20 percent more than Shyam's.
Solution:
The salary of Ram = (120/100) × The salary of Shyam
The salary of Shyam = (100/120) × The salary of Ram
The salary of Shyam = 5/6 × The salary of Ram
That is, the Salary of Shyam is (1/6) less than the salary of Ram.
In percentage terms = (1/6) × 100 = 16.66%.
Alternate Solution 1:
Let Shyam's salary be Rs 100
Then, Ram's salary = 100 × 120% = Rs 120
Difference between their salary = 120 - 100 = Rs 20
Shyam's salary less than Ram in percentage = $$\frac{20}{120}$$​ × 100 = $$\frac 16$$​ × 100 = 16.66% 
Alternate Solution 2: 
Ram  :  Shyam 
  6       :   5
Required Percentage = $$\frac{6-5}{6} \times 100 = 16.66\%$$