| Difficulty | Secondary School | High school/other |
| ★ | Basic | Easy |
| ★★ | Demanding | Basic |
| ★★★ | Demanding | |
| ★★★★ | Difficult | |
| ★★★★★ | Very difficult |
a) Define the total resistance. b) How high is the resistance with one resistor? The components in the video are standard resistors with the same resistance.
Answer: a) $110\ \Omega$, b) $210\ \Omega$