1. Two phone plans have costs modeled by $C_1(m) = 20 + 0.10m$ and $C_2(m) = 30 + 0.05m$, where $m$ is minutes used. Which inequality represents when Plan 1 is cheaper than Plan 2?
2. The value of two cars is modeled by $V_A(t) = 25000 - 1500t$ and $V_B(t) = 20000 - 1200t$, where $t$ is years. To find when Car A's value is more than Car B's, you solve $V_A(t) >$ ___.
3. The number of bacteria in two cultures are $A(h) = 500(1.1)^h$ and $B(h) = 800(1.05)^h$, where $h$ is hours. Which inequality models when Culture A's population is at least that of Culture B?
4. Two stocks' values are $S_1(d) = 50(1.02)^d$ and $S_2(d) = 40(1.03)^d$. The condition that Stock 2's value will exceed Stock 1's value is modeled by the inequality $40(1.03)^d >$ ___.
5. The profits of two stores are given by functions $f(x)$ and $g(x)$. To find when the profit of store $f$ is no more than the profit of store $g$, which inequality should be solved?
6. A function $f$ satisfies the property $f(ab) = f(a) + f(b)$ for all positive integers $a, b$. If $f(3) = 4$, what is the value of $f(81)$? The value is ___.
7. A function $f$ has the property that $f(x + y) = f(x) + f(y)$. If $f(1) = 5$, what is the value of $f(4)$?
8. Let $g$ be a function such that $g(x + y) = g(x) \cdot g(y)$ for all $x, y$. If $g(1) = 2$, what is the value of $g(4)$? The value is ___.
9. A function $h$ satisfies the rule $h(3x) = 3h(x)$ for all values of $x$. If $h(2) = 5$, what is the value of $h(18)$?
10. A function $f$ has the property $f(xy) = f(x) + f(y)$. If $f(25) = 10$, what is the value of $f(5)$? The value is ___.