If the third number in the list is 0.064, what is the first number in the list?

Explain how you know

Since the problem states that the numbers form a list, therefore this means that there is equal spacing between the numbers. For example, 1, 2, 3 are a list where 3 is the third number. The spacing between them is increment of 1.

Now since 0.064 is the third number, therefore the first number must be:

0.064 / 3 = 0.021

Answer:

0.021