A hospital nursery has 3 boys and some girls. A child was selected at random what is the probability that the child is a boy?

To determine the probability that the selected child is a boy, we need to know the total number of children in the hospital nursery and the number of boys. The given information states that there are 3 boys, but it doesn't specify the total number of children. Let's assume there are "n" total children in the nursery, including boys and girls.

The probability of an event happening is defined as the number of favorable outcomes divided by the total number of possible outcomes. In this case, the favorable outcome is a boy being selected, and the possible outcomes are all the children in the nursery.

So, the probability of selecting a boy is equal to the number of boys divided by the total number of children:
P(boy) = Number of boys / Total number of children

Since there are 3 boys, the numerator (number of boys) is 3. However, we don't know the value of the denominator (total number of children) given in the question. Without knowing the total number of children, it is not possible to calculate the exact probability.

To determine the probability of selecting a boy, we need to have the total number of children in the nursery.