Hector types at a rate of 40 words per
minute. The equation w = 40m describes the
relationship between w, the number of words
he types, and m, the number of minutes he
spends typing. Which statement is true?
A The rate at which Hector types depends
on the number of minutes he spends
typing.
B The number of minutes he spends typing
depends on the number of words he types.
C The number of words he types depends on
the number of minutes he spends typing.
D The rate at which Hector types depends
on the number of words he types.