The complete question is: how to find the unit rate for 325 meters in 28 seconds.
Remember that a rate is a ratio that compares quantities of different units; in our case we are comparing meters and seconds. A unit rate is a rate expressed as a quantity of one; in other words the second quantity is one unit. To express a ratio as a unit rate, just divide the numerator by the denominator.
The rate between our quantities is
. To express our rate as a unit rate, we just need to express the second quantity as 1. To do it, we just need to divide the numerator 325 by the denominator 28:
We can conclude that the correct answer is
, or using words 11.71 meters per second.