1. Analyzing Statement I:
- It states that the difference between their typing speeds is 10 words per minute, but we don't know their individual speeds.
- Not sufficient.
2. Analyzing Statement II:
- It states that Sapna types at 80 words per minute, but we don't know Navin's speed or their difference in typing speed.
- Not sufficient.
3. Combining both Statements:
- Even though we know Sapna's speed and the difference, we still cannot determine who types faster, as the difference could be positive or negative.
- Together, the statements are still not sufficient.