What is the missing number here?

The correct answer to the question “2, 6, 1, 3, 0.5, 1.5, ? What is the missing number?” is0.25. Here is the basic explanation to this answer. If you will look at the numbers 2, 1, and 0.5, you will notice the number 1 reflects the half of 2, and 0.5 reflects the half of 1. Now, look at numbers 6, 3, and 1.5, you will also notice that number 3 is the half of 6, and number 1.5 is the half of 3.

Now that we finally settled that the sequence is just the half of another number, then we can conclude that 0.25 is the half of 0.5, which in turn, completes the sequence and answers the question being asked.