Question

In a math class, there are 12 girls and 13 boys. The teacher asks for two volunteers to come to the board one at a time. What is the probability that the first student is a girl and the second student is a boy? answer choices: 156/625 2/25 1/156 13/50

Answer 1

In the class there is a total of students of 25, so the probabilitie that the first studen is a girl will be:

$P_1=\frac{12}{25}=0.48$

Now without the first students there will be 24 studends so the probability that the second student is a boy will be:

$P_2=\frac{13}{24}=0.54$

Now the probabilitie that bout of them happen will be the multiplication of the probabilities so:

$\begin{gathered} P_t=P_1\cdot P_2 \\ P_t=\frac{12}{25}\cdot\frac{13}{24} \\ P_t=\frac{156}{600}=\frac{78}{300}=\frac{39}{150}=\frac{13}{50} \end{gathered}$

So the probabilitie will be 13/50