Liz is a jabber-mouth; she can speak 225 words in 5 minutes.

Question

b

Find the constant of variation. 

Do these quantities (number of words and time) vary directly or inversely?

Answer 1

225 words/ 5 min = 45 words/ minute

These values vary directly. Direct variation looks like this:

x/y = k ( a constant)

Inverse variation looks like this:

xy = k (a constant)