Question

an item is randomly drawn from a drawer with 4 blue markers, 7 red markers, 6 blue pens, and 3 green pens. event a: marker event b: blue p(a or b) = ? hint: p(a or b) = p(a) + p(b) - p(a and b) round your answer to the nearest hundredth

Explanation:

Step1: Calculate total number of items

$4 + 7+6 + 3=20$

Step2: Calculate P(A)

Number of markers is $4 + 7=11$, so $P(A)=\frac{11}{20}$

Step3: Calculate P(B)

Number of blue items is $4+6 = 10$, so $P(B)=\frac{10}{20}$

Step4: Calculate P(A and B)

Number of blue - markers is 4, so $P(A\ and\ B)=\frac{4}{20}$

Step5: Calculate P(A or B)

Using the formula $P(A\ or\ B)=P(A)+P(B)-P(A\ and\ B)$, we have $P(A\ or\ B)=\frac{11}{20}+\frac{10}{20}-\frac{4}{20}=\frac{11 + 10-4}{20}=\frac{17}{20}=0.85$

Answer:

$0.85$