In a class of 30 students, A is ranked 12th from the top. What is A's rank from the bottom?

A. 19TH

B is ranked 5th from the bottom in a group of 25 people. What is B's rank from the top?

B. 20TH

In a class of 30 students, John is ranked 12th from the top. What is his rank from the bottom?

B. 18TH

In a class of 30 students, A is ranked 10th from the top. What is A's rank from the bottom?

B. 21ST

In a race of 15 participants, if Sam is 3rd from the top and 13th from the bottom, how many participants are there in total?

A. 15