The average marks obtained by a class of $60$ students is $05.$ The average marks of half of the students is found to be $85 .$ The average marks of the remaining students is
$35$
$45$
$55$
$65$
Of the three numbers, the average of the first and the second is greater than the average of the second and the third by $15 .$ What is the difference between the first and the third of the three numbers?
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 contribution of $5$ men to a fund is $Rs.\,35.$ A sixth man joins and pays $Rs.\,35$ more than the resultant average of $6$ men. The total contribution of all the six men is (in $Rs.$)
The average of $11$ numbers is $10.9$ If the average of the first six is $10.5$ and the average of last six is $11.4,$ find the middle (sixth) number.
The average of $13$ results is $50 .$ If the average of first $7$ results is $52$ and that of last $7$ results is $49,$ find the $7^{th}$ result.