Questions

Here in the given number puzzle, the given numbers follows a pattern that 

1 + 4 = 5 => 1 x 4 + 1 = 4 + 1 = 5 

2 + 5 = 12 => 2 x 5 + 2 = 10 + 2 = 12   

3 + 6 = 21 => 3 x 6 + 3 = 18 + 3 = 21 

Similarly, 

8 + 11 = 96 => 8 x 11 + 8 = 88 + 8 = 96  

Hence, the missing number in the given number puzzle is 96.

Any of the basic mechanical devices for applying a force are called simple machines.

There are 6 basic simple machines; the lever, the wheel and axle, the inclined plane, the wedge, the pulley, and the screw. Several of these simple machines are related to each other. But, each has a specific purpose in the world of doing work.