A teacher chooses a student at random from a class of 20 boys. What is the probability that the student chosen is a boy?
There are 35 students in a class of whom 20 are boys and 15 are girls. From these students one is chosen at random. What is the probability that the chosen student is a (i) boy, (ii) girl?
In a class of 30 students, there are 17 girls and 13 boys. If a student is chosen at random, what is the probability of choosing a girl student?