Ravi ranks 12th from the top and 21st from the bottom in a class. How many students are there in the class? ​​

Given: 

Ravi ranks 12th from the top and 21st from the bottom in a class.

Total = Rank from top + Rank from bottom - 1

= 12 + 21 - 1

= 33 - 1 

= 32

So, 32 students are there in the class.

Thus, correct option is (d).