What is the difference between the number of students in class vi and class xi ?

Q.

If in class XI of a certain school, 24 students got distinction in mathematics, 19 students got distinction in physics and 15 students got distinction in both the subjects,then the number of students in class XI is :

Q. There are $5$ brilliant students in class $XI$ and $8$ brilliant students in class $XII.$ Each class has $50$ students, The odds in favour of choosing the class $XI$ are $2:3,$ If the class $XI$ is not chosen then the class $XII$ is chosen, A student is a chosen and is found to be brilliant, find the probability that the chosen student is from class $XI.$

Q. Total number of students in 4 different schools and percentage of students participating in Dance and play in 4 different classes:
Q. If 20% of students who participate in dance from class VI also participate in play then find the ratio of student from class VI who participated only in dance to students participated only in play?

Q. Total number of students in 4 different schools and percentage of students participating in Dance and play in 4 different classes:
Q. What is the ratio of students participating in Dance from Class VII and IX togerher to the students participating in Play from Class VI and VIII together?

Q. There are $40$ students in Joe's class. In a $20$ marks class test, $10$ students got $16$ marks, $20$ students got $15$ marks and rest $10$ students got $10$ marks. The weighted average of marks in Joe's class is .