Around 61% of the runners finished in less than 30 minutes.
We first find the total number of runners represented in the graph by adding the heights of all of the bars:
2+6+9+8+3 = 28 runners
Now we add the heights of the bars representing less than 30 minutes:
2+6+9 = 17
To find the percentage we divide the number of runners finishing in less than 30 minutes by the total number of runners:
17/28 = 0.607 ≈ 0.61 = 61%