The average marks obtained by the students in a class are 43. If the average marks obtained by 25 boys are 40 and the average marks obtained by the girl students are 48, then what is the number of girl students in the class?

The average marks obtained by 100 candidates in an examinatiion are 45. If the average marks of the passed students are 50 while the average marks of the failed students is 40. Then find the number of students who passes the examination.

The average marks obtained by 15 students including x are 70 and the average marks obtained by 14 students excluding x is 68. What is the marks obtained by x-

What are the average marks obtained by all the students together in Science ?

The average marks obtained by 150 students in an examination is 40. If the average marks of passed students is 60 and that of the failed students is 20, then what is the number of students who passed the examination?