PHP Compiler Testing
Folding a Piece of Paper

Create a function that returns the thickness (in meters) of a piece of paper after folding it n number of times. The paper starts off with a thickness of 0.5mm.

Examples

num_layers(1) ➞ "0.001m"

# Paper folded once is 1mm (equal to 0.001m)

 

num_layers(4) ➞ "0.008m"

# Paper folded 4 times is 8mm (equal to 0.008m)

 

num_layers(21) ➞ "1048.576m"

# Paper folded 21 times is 1048576mm (equal to 1048.576m)