Question

.002 is 1/10 of what

Answer 1

This uses the concept of proportions.

.002 converted to a fraction is 2/1000, or 1/500.

We set up the proportion like so:
 10/100 = .002/x 
Solve for x.

Cross-multiply.
10 * x = .002 * 100
10 * x = .2
x = .2 / 10
x = .02

The answer is .02