The balance, $B$, in dollars, in a bank account depends on the amount deposited, $A$ dollars, the annual interest rate, $r$ %, and the time, $t$, in months since the deposit, so $B=f(A,r,t)$.

(a) Is $f$ an increasing or decreasing function of:
$A$? ? increasing decreasing neither increasing nor decreasing somtimes increasing and sometimes decreasing
$r$? ? increasing decreasing neither increasing nor decreasing somtimes increasing and sometimes decreasing
$t$? ? increasing decreasing neither increasing nor decreasing somtimes increasing and sometimes decreasing

(b) Interpret the statement $f(1250, 2.75, 20) \approx 1977$ by writing a sentence, including units. Then use your sentence to complete the following:
The units of 1250 are: ? percent months dollars dollars/month percent/month
The units of 2.75 are: ? percent months dollars dollars/month percent/month
The units of 20 are: ? percent months dollars dollars/month percent/month
The units of 1977 are: ? percent months dollars dollars/month percent/month .

(Note because this is all multiple choice, you will not see which parts of the problem are correct.)