The equation above models the number of members, M, of a gym t years after the gym opens. Of the following, which equation models the number of members of the gym q quarter years after the gym opens?
Choice A is correct. In 1 year, there are 4 quarter years, so the number of quarter years, q, is 4 times the number of years, t ; that is, . This is equivalent to
, and substituting this into the expression for M in terms of t gives
.
Choices B and D are incorrect and may be the result of incorrectly using instead of
. (Choices B and D are nearly the same since
is equivalent to
, which is approximately
.) Choice C is incorrect and may be the result of incorrectly using
and unnecessarily dividing 0.02 by 4.