85 percent, and Day 11.
This is Graphics Interpretation, and the only hard part is reading the bar edges. Bars break on the gridlines between the day labels, not on the labels themselves, so Artifact selection running from the left edge to the line just past 3 covers days 1, 2 and 3. Get that half-step wrong and every count after it shifts.
Reading them off:
1. Curation: Artifact selection days 1 to 3, Label drafting 4 to 6, Content approval 10 to 11.
2. Design: Layout planning 3 to 5, Lighting plan 6 to 8, Signage design 11 to 13.
3. Installation: Display fabrication 7 to 11, Case installation 10 to 13, Final placement 13 to 15.
4. Media: Media scripting 5 to 7, Interactive setup 9 to 12, Press preview 14 to 15.
First blank. Count teams, not bars. Days 1 and 2 have only Curation working. Every day from 3 onward has at least two teams on it, so 13 of the 15 days qualify. 13/15 is 86.7 percent, and the nearest 5 percent is 85.
Second blank. Don't test all fifteen days. Curation is the scarcest team, scheduled only on days 1 to 6 and 10 to 11. Design overlaps that on days 3, 4, 5, 6 and 11. Installation doesn't start until day 7, which kills the first four. Day 11 is the only survivor, and it holds up: Content approval, Signage design, Display fabrication, Case installation and Interactive setup. Four teams, five tasks.
That gap between tasks and teams is the trap. Installation runs two tasks at once on day 11 and again on day 13, so counting bars instead of teams inflates both days.
On any Gantt-style chart, find the series with the fewest scheduled days and use it to cut the candidate list before you check anything else.