In an examination, out of $20$ students in a class, in Mathematics $2$ students scored $100$ marks $, 3$ students scored $0,$ and average marks for rest of the students was $40 .$ What is the average mark of the whole class ? (in $marks$)

The average marks in English of a class of $24$ students is $56 .$ If the Marks of three students were misread as $44,45$ and $61$ in lieu of the actual marks $48,59$ and $67$ respectively, then what would be the correct average ?

The sum of three consecutive even numbers is $28$ more than the average of these three numbers. Then the smallest of these three numbers is

The average of marks obtained by $150$ candidates in a certain examination is $50 .$ If the average marks of passed candidates is $55$ and that of the failed candidates is $25,$ what is the number of candidates who passed the examination?

The average marks of a group of $20$ students on a test is reduced by $4$ when the topper who scored $90$ marks is replaced of a new students. Find the marks of the new student.