Spinner Probability Log Equation Area
1. Problem 18: Mutoni spins 2 spinners; one with colors Red (R), Yellow (Y), Blue (B), and the other with Green (G), White (W), Purple (P).
2. a) Draw a tree diagram: The first spinner has 3 outcomes (R, Y, B). Each branches into 3 outcomes of the second spinner (G, W, P). So total outcomes are 3 \times 3 = 9.
3. b) Probability spinners stop at B and G:
- Probability first spinner stops at B is $\frac{1}{3}$.
- Probability second spinner stops at G is $\frac{1}{3}$.
- Since independent, combined probability is $\frac{1}{3} \times \frac{1}{3} = \frac{1}{9}$.
4. c) Probability spinners do not stop at B and G:
- Probability of B and G is $\frac{1}{9}$.
- Probability of not (B and G) is $1 - \frac{1}{9} = \frac{8}{9}$.
5. d) Probability first spinner does not stop at R:
- Probability first spinner stops at R is $\frac{1}{3}$.
- So probability it does not stop at R is $1 - \frac{1}{3} = \frac{2}{3}$.
6. Problem 19: Solve equation
$$\frac{\log_4 x^2}{5 + \log_4 x^2} + (\log_4 x)^2 = 0$$
7. Let $y = \log_4 x$.
Then $\log_4 x^2 = 2y$.
Rewrite equation:
$$\frac{2y}{5 + 2y} + y^2 = 0$$
Multiply both sides by $5 + 2y$:
$$2y + y^2(5 + 2y) = 0$$
Expand:
$$2y + 5y^2 + 2y^3 = 0$$
Rewrite:
$$2y^3 + 5y^2 + 2y = 0$$
Factor out $y$:
$$y(2y^2 + 5y + 2) = 0$$
8. Solve $y=0$ or $2y^2 + 5y + 2=0$.
- For $y=0$, $\log_4 x = 0 \Rightarrow x = 4^0 = 1$.
- For quadratic, use formula:
$$y = \frac{-5 \pm \sqrt{25 - 16}}{4} = \frac{-5 \pm 3}{4}$$
9. Roots:
- $y = \frac{-5 + 3}{4} = \frac{-2}{4} = -\frac{1}{2}$
- $y = \frac{-5 - 3}{4} = \frac{-8}{4} = -2$
10. Convert back to $x$:
- For $y = -\frac{1}{2}$, $x = 4^{-1/2} = \frac{1}{\sqrt{4}} = \frac{1}{2}$.
- For $y = -2$, $x = 4^{-2} = \frac{1}{16}$.
11. Final solutions for $x$ are:
$$x = 1, \frac{1}{2}, \frac{1}{16}$$
12. Problem 20: Find total area of garden.
- Area1 is a square with side length 2m, so area is $2 \times 2 = 4$ m$^2$.
- Area2 is a rectangle adjacent to Area1 with height 2m.
- Total length of two zones combined is 10m.
- Since Area1 is square with length 2m, Area2 length is $10 - 2 = 8$ m.
- Area2 area is $8 \times 2 = 16$ m$^2$.
13. Total area of garden is sum of areas:
$$4 + 16 = 20 \text{ m}^2$$
Final answers:
- 18b) $\frac{1}{9}$
- 18c) $\frac{8}{9}$
- 18d) $\frac{2}{3}$
- 19) $x = 1, \frac{1}{2}, \frac{1}{16}$
- 20) Total area = 20 m$^2$