Group $2(4$ questions for $40$ points in total$).$ Multiple choice single$-$correct questions.

Consider a query $($suppose we only use this query to evaluate the systems$)$ for which there are $4$ relevant documents in the collection. Compare two systems that run on this collection. Their top $10$ results are judged for relevance as follows $($the leftmost item is the top ranked search result$)$:

System $1$: R N R N N N N N R R

System $2$: N R N N R R R N N N