The partially completed histogram and the partially completed table show the times taken, to the nearest second, for a group of people to complete a puzzle.

| Time (seconds) | Frequency |
|---|---|
| 1 – 4 | 2 |
| 5 – 8 | 12 |
| 9 – 10 | 8 |
| 11 – 15 | |
| 16 – 20 | 3 |
Complete the table.
Complete the histogram
One of the participants is selected at random. Estimate the probability that this participant completed the puzzle in under 10 seconds.