Question

a jar contains white, red and blue marbles. the probability of pulling a red marble is 0.35 and a blue marble 0.25. what is the probability of pulling a white marble?

Explanation:

Step1: Recall the probability sum rule

The sum of probabilities of all mutually - exclusive events is \(1\). Let \(P(R)\) be the probability of red, \(P(B)\) be the probability of blue, and \(P(W)\) be the probability of white. So \(P(R)+P(B)+P(W) = 1\).

Step2: Substitute the given values

We know that \(P(R)=0.35\) and \(P(B) = 0.25\). Substitute these into the equation: \(0.35+0.25+P(W)=1\).

Step3: Solve for \(P(W)\)

First, calculate \(0.35 + 0.25=\frac{35}{100}+\frac{25}{100}=\frac{35 + 25}{100}=0.6\). Then, from \(0.6+P(W)=1\), we can find \(P(W)=1 - 0.6\).

Answer:

\(0.4\)