Border Patrol Practice Exam

The probability of selecting a carton of prohibited fruit is determined by the ratio of the number of cartons identified as prohibited to the total number of cartons. In this scenario, the dog identified 20 cartons as prohibited out of 120 total cartons.

To calculate the probability, you divide the number of prohibited cartons (20) by the total number of cartons (120):

\[

\text{Probability} = \frac{\text{Number of prohibited cartons}}{\text{Total number of cartons}} = \frac{20}{120}

\]

When you simplify the fraction \( \frac{20}{120} \), both the numerator and denominator can be divided by 20:

\[

\frac{20 \div 20}{120 \div 20} = \frac{1}{6}

\]

Thus, the calculated probability of selecting a carton of prohibited fruit is \( \frac{1}{6} \). This calculation reflects the fundamental principle of probability, which involves finding the likelihood of a specific outcome in relation to all possible outcomes.