Nomsi was on holiday for 7 weeks and 2 days. She spent the first 3 weeks and 5 days at her grandmother's house. How long did she spend on the rest of her holiday?

Total holiday duration = 7 weeks and 2 days
Duration at grandmother's house = 3 weeks and 5 days

Since 2 days is less than 5 days, we need to borrow 1 week from the 7 weeks.
1 week = 7 days.
So, 7 weeks and 2 days becomes 6 weeks and $(2 + 7)$ days, which is 6 weeks and 9 days.

Subtract the days: $9 \text{ days} - 5 \text{ days} = 4 \text{ days}$
Subtract the weeks: $6 \text{ weeks} - 3 \text{ weeks} = 3 \text{ weeks}$

The remaining holiday duration is 3 weeks and 4 days.

The final answer is $\text{3 weeks and 4 days}$.