Question

one number is chosen at random from the set {3, 4, 5, 7, 9}. find the chance of choosing: (a) an even number 15% 20% 25% 40%

Explanation:

Step1: Count total numbers

Total numbers: $n(\text{total}) = 5$

Step2: Count even numbers

Even numbers in set: $\{4\}$, so $n(\text{even}) = 1$

Step3: Calculate probability

Probability: $\frac{n(\text{even})}{n(\text{total})} = \frac{1}{5} = 0.2$

Step4: Convert to percentage

Percentage: $0.2 \times 100\% = 20\%$
*Correction: Error in Step2, even numbers are {4}, count=1. Wait, no: $\frac{1}{5}=0.2=20\%$. So correct answer is B. 20%

Step1: Count total elements

Total elements: $5$

Step2: Identify even elements

Even element: only $4$, count $=1$

Step3: Compute probability

Probability: $\frac{1}{5} = 0.2$

Step4: Convert to percentage

Percentage: $0.2 \times 100\% = 20\%$

Final Answer:

B. 20%

Answer:

D. 40%