To find the equivalent unit rate, you take the smaller number, and divide the bigger number by that.
A.) 108/4=27
So, that would be 27 words in one minute. The goal to find one of the vaults to be one. Usually the time.
B.) 300/15=20
So, your answer would be 20 miles in one hour
C.) 102.5/10=10.25
The answer would be 10.25 for an hour. Feel free to ask questions!