Question

what is the probability the spinner below will land on a or b? a p(a or b)=0.125 b p(a or b)=0.overline{6} c p(a or b)=0.5 d p(a or b)=0.75

Explanation:

Step1: Analyze the spinner

The spinner is divided into 4 equal parts (since it looks like a circle split into 4 sections: A, B, and two others? Wait, looking at the diagram, A is half the circle (2/4), B is 1/4, and C is 1/4? Wait, no, the diagram shows A as a semicircle (2/4), B as a quarter circle (1/4), and C as a quarter circle (1/4). Wait, actually, the circle is divided into 4 equal sectors? Wait, no, A is a larger sector (half the circle), B is a quarter, and C is a quarter? Wait, no, the spinner has three regions? Wait, no, the diagram: A is a semicircle (180 degrees), B is a quarter circle (90 degrees), C is a quarter circle (90 degrees). So total parts: A is 2/4, B is 1/4, C is 1/4.

Step2: Calculate probability of A or B

Probability of A: \( P(A) = \frac{2}{4} = 0.5 \)
Probability of B: \( P(B) = \frac{1}{4} = 0.25 \)
Since A and B are mutually exclusive (can't land on both at the same time), \( P(A \text{ or } B) = P(A) + P(B) = 0.5 + 0.25 = 0.75 \)

Answer:

D. \( P(\text{A or B}) = 0.75 \)