# Problem
Run the demo program with a delay of 100 milliseconds in the loop and observe what happens when a full cycle of a rectangular wave takes 1.6 seconds to complete. This can be done with `delay_tenths_ms(1000)`.
## 1.
What happens when the switches are set to `0b1111`, or 15 in decimal?
## 2.
What is the duty cycle (in percent) when the switches are set to `0b1111`?
# Process
## 1.
When the switches are set to `0b1111`, or 15 in decimal, the LEDs don't flicker.
## 2.
...
# Answer
## 1.
The LEDs don't flicker.
## 2.
100% duty cycle.