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

A. 1

In the sequence 0, 1, 2, 3, 4, 5, how many times does the number 3 occur?

A. 1

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

A. 1

In the sequence 0, 1, 2, 3, 4, 5, how many times does the number 6 occur?

D. 0

In the sequence 12, 15, 18, 21, 24, 27, how many times does the number 21 occur?

A. 1