Solve the following problem: Write $\mathrm{W}$ in the box if the answer is a whole number else write $\mathrm{X}$:

$262-\left(100+99+63\right)=$_____

 

The number represented by the shaded part of the given shape is _____.

Solve the following problem: Write $\mathrm{W}$ in the box if the answer is a whole number else write $\mathrm{X}$:

$834-900=$_____

Solve the following problem: Write $\mathrm{W}$ in the box if the answer is a whole number else write $\mathrm{X}$:

$1\times 101\times 1001=$_____