Which expressions are equivalent to 1/5 • 1/5 • 1/5 • 1/5

1/625

Step-by-step explanation:

The dots between the fractions mean multiply. Multiply all the numerators together, then all the denominators.

     1x1x1x1 = 1

5×5×5×5 = 625

If you put it in a calculator, you get 0.0016

or as an exponential expression  or  

Negative exponents mean "the reciprocal of the base to the power"

in this case, 5^4 is and that's 625. the reciprocal is 1/625.

i believe the correct answer is b.