Final answer:
In a class of 10 boys and 8 girls, the probability of selecting 3 boys at random can be calculated using the combination formula.
Step-by-step explanation:
To find the probability that all the students selected are boys, we need to find the number of favorable outcomes and divide it by the total number of possible outcomes.
There are 10 boys and 8 girls in the class. The teacher needs to select 3 students.
The number of ways to select 3 boys from 10 boys is given by the combination formula: C(10, 3).
The total number of ways to select 3 students from a class of 10 boys and 8 girls is given by the combination formula: C(18, 3).
Therefore, the probability that all the students selected are boys is:
P(3 boys) = C(10, 3) / C(18, 3)