When you multiply a number by
1
4
, the result is
a) 50% of the original number.
b) 400% of the original number.
c) four times the original number.
d) one-fourth the original number.

D) 1/4.

The equation would look like:

1/4 * n

Where n is some random number. You read the equation this way:

     1/4         *        n    =   x
       ↑          ↑        ↑    ↑   ↑
one fourth  of       n   is   x

The answer is part a: use