The average age of a graph of $9$ students is $20\, years.$ When $6$ more students joined the group, the average age falls by $2\, years.$ Then the average age of new students is
$20$
$18$
$19$
$15$
The average of nine numbers is $50.$ The average of the first five numbers is $54$ and that of the last three numbers is $52 .$ Then the sixth number is?
A batsman has an average of $30$ runs in his $42$ inning. The difference between his maximum and minimum score is $100 .$ If these two innings are removed his average for $40$ innings comes down to $28 .$ What is his minimum score?
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
The mean of $100$ items was $46 .$ Later on, it was discovered that an item $16$ was misread as $61$ and another item $43$ was misread as $34.$ It was also found that the number of items was $90$ and not $100 .$ Then, what is the correct mean?
Sachin Tendulkar has a certain average for $11$ innings. In the $12^{th}$ innings he scores $120$ runs and thereby increases his average by $5$ runs. His new average is