Find the maximum length of a rod with negligible thickness which can be fitted into a cubical bo of 1 meter length of each side.

What is the total number of circles in the figure given below?

One line forms two regions in a plane.Similarly, two lines in a plane can form a maximum of four regions. These are shown in the figures below:

What is the maximum number of regions that can be formed by $4$ lines in a plane? Lines need not be concurrent.

A coin is in a fixed position. Another identical coin is rolled around the edge of the first one. How many complete revolutions made by the revolving coin before it reaches its starting position. 

If $\times$ stands for $+$,$÷$ stands for $-$, $+$ stands for $÷$ and  $-$ stands for, then what is the value of the following  expression?

$÷33\times 11÷9\times 28+4-5$

If $\text{'}⅀\text{'}$ means $\text{'}x\text{'}$,$\text{'}\delta \text{'}$  means $\text{'}÷\text{'}$ , $\text{'}\sigma \text{'}$  means$\text{'}+\text{'}$ ,  $\text{'}\alpha \text{'}$ means $\text{'}-\text{'}$ then evaluate the following expression using standard operator precedence.

$56\delta \left(6\sigma 8\right)⅀4\alpha 1$