Rahul ranked ninth from the top and thirty-eighth from the bottom in a class. How many students are there in the class?

In a queue of children,Kashish is $5^{th}$ from the left and Mona is $6^{th}$ from the right. When they interchange their places among themselves,Kashish becomes $13^{th}$ from the left. Then,what will be Mona's position from the right (in $^{th}$)?

Given the series: $7, 8, 9, 7, 6, 5, 3, 4, 2, 8, 9, 7, 2, 4, 5, 9, 2, 9, 7, 6, 4, 7$. Which numbers have equal frequency?

Among five friends,Mahesh is taller than Karan but not Yash. Hrithik is taller than Yash but not Abhishek. If they stand in increasing order of their heights,who will be first in line?

How many $3$'s are there in the following sequence which are neither preceded by $6$ nor immediately followed by $9$?
$9, 3, 6, 6, 3, 9, 5, 9, 3, 7, 8, 9, 1, 3, 9, 6, 3, 9$

Among $B, F, J, K$ and $W$ each having a different weight, $F$ is heavier than only $J.$ $B$ is heavier than $F$ and $W$ but not as heavy as $K.$ Who is the third heaviest among them?