Final answer:
To find the percent of Jess' gatherings that were driftwood, subtract the percent of sea shells and rocks from 100%. The percent of driftwood is 11%.
Step-by-step explanation:
To find the percent of Jess' gatherings that were driftwood, we need to subtract the percent of sea shells and rocks from 100%. Since Jess' gatherings were 86% sea shells and 3% rocks, the percent of driftwood can be calculated as:
100% - 86% - 3% = 11%
Therefore, 11% of Jess' gatherings were driftwood.