In a quiz competition, Tom is ranked 10th from the top and after swapping places with another participant, he is now ranked 15th from the top. How many participants are there in total?

B. 21

In the sequence 100, 200, 300, 400, 500, how many times does the number 600 occur?

B. 0

In the sequence 5, 10, 15, 20, 25, 30, how many times does the number 25 appear?

A. 1

In the sequence 2, 4, 6, 8, 10, 12, how many times does the number 5 occur?

A. 0

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

B. 19TH