Vvaries inversely with t and v = 18 when t = 3. which equation shows this relationship?
a)v=54/t
b)v=6/t
c)v=54t
d)v=6t

The phrase "varies inversely" means that the value of V increases when T decreases and it decreases if otherwise. Let k be the constant of this inverse variation such that, 
                                        V = k/T
Substituting the given values,
                                        18 = k/3
The value of k is 54. Thus, the inverse variation may be written as,
                                         V = 54/T
Among the choices, the answer would be letter A. v = 54/T.