You should just be relatively honest about your three greatest strengths, while avoiding overconfident answers like intelligence. Passion, attitude, leadership, intellectual curiosity, work ethic, and resilience are some examples.
First, list your 3 strengths. Then use this opportunity to tell a quick story about each strength and provide an example from work, school, or extracurricular experiences.
You won’t have time to go in-depth into each example. For each example, just provide the general context, the most pertinent details, and the result in a few sentences.
Feel free to conclude your answer by repeating your three strengths again as a smooth way to end your answer.