Differentiation...

A Printer number the pages of a book starting with $1$ and used $3193$ digit in all. How many pages does the book have:

The number of permutations of letters of the word "PARALLAL" atken four at a time must be, 

If $(\cos x)^{y}=(\sin y)^{x}$, then $\dfrac{dy}{dx}=$

7, 11, 23, 51, 103 ?

Using all digits $2,3,4,5,6$ how many even number can be formed 

13, 16, 22, 33, 51 ?

655, 439, 314, 250, 223 ?

If $y = \exp \left\{ {{{\sin }^2}x + {{\sin }^4}x + {{\sin }^6}x + ....} \right\}$ then $\frac {dy}{dx}=$

The differential of $f(x)=\sqrt{\dfrac{2-x}{2+x}}$ at $x=0$ and $\delta x=0.15$ is

Six people are going to sit in a row on a bench. $A$ and $B$ are adjacent, $C$ does not want to sit adjacent to $D.E$ and $F$ can sit anywhere. Number of ways in which these six people can be seated is