Question

There are $30$ boys and $25$ girls in a class. A student is chosen at random. Find the probability that the chosen student is a boy.

Answer 1

Find the probability that the chosen student is a boy

1. Probability is a measure of the likelihood of an event to occur.
2. The probability of all the events in a sample space adds up to $1$.

Number of boys $=30$

Number of girls $=25$

Therefore, the total number of students $30+25=55$

$n\left(S\right)=55$

Let $X$ be the event of choosing a boy.

Therefore, $n\left(X\right)=30$

Therefore, the probability of choosing a boy, $P\left(X\right)=\frac{n\left(X\right)}{n\left(S\right)}$

$P\left(X\right)=\frac{30}{55}$

$P\left(X\right)=\frac{6}{11}$

Hence, the probability that the chosen student is a boy $\frac{6}{11}$.