22. Five mark exercise problem X

In a class of $35$, students are numbered from $1$ to $35$. The ratio of boys to girls is $4:3$. The roll numbers of students begin with boys and end with girls. Find the probability that a student selected is either a boy with a prime roll number or a girl with a composite roll number or an even roll number.Answer:

 

The required probability is $\frac{i}{i}$.