Series or parallel: which gives more resistance?

You have three resistors: $5\ \Omega$, $10\ \Omega$ and $20\ \Omega$. You will make the program find their combined resistance in series and in parallel, and how many times larger the series value is. Then it draws the two as bars.

Your tasks.

1. Find series, the combined resistance in series.
2. Find parallel, the combined resistance in parallel.
3. Find ratio, the series value divided by the parallel value.