How many numbers from $11$ to $50$ are there which are exactly divisible by $7$ but not by $3$?

Geeta is senior to Shilpa but not to Deepa. Gayatri is junior to Reepa. No one is senior to Fatima. Who is most junior?

In a row of children facing North,Ritesh is $12^{th}$ from the left end. Sudhir,who is $22^{nd}$ from the right end,is $4^{th}$ to the right of Ritesh. How many children are there in the row in total?

In the sequence $7, 8, 9, 7, 6, 5, 3, 4, 2, 8, 9, 7, 2, 4, 5, 9, 2, 9, 7, 6, 4, 7$,how many $7$'s are preceded by $9$ and followed by $6$?

How many $8$'s are there in the following number series which are exactly divisible by their immediately preceding and also divisible by their immediately succeeding numbers?
$8, 2, 4, 5, 1, 7, 2, 8, 4, 8, 4, 2, 2, 8, 2, 6, 9, 8, 4, 5, 4, 8, 3, 2, 8, 4, 3, 1, 8, 3$

If $18^{th}$ February,$1997$ falls on Tuesday,then what will be the day on $18^{th}$ February,$1999$?