Update assessment-cp.md

morea/cond_prob/assessment-cp.md

@@ -67,7 +67,7 @@ problems in the previous module.
 	   
 	  3. When _Quicksort_ is called on the two subsequences of length $$L_1$$ and $$L_2$$, each call produces a new pivot, say $$p_1$$ and $$p_2$$ respectively. Conditioned on any choice of $$p_0$$, the two pivots are chosen independently. But are $$p_1$$ and $$p_2$$ independent? (You can tell whether they are independent without any calculation).
 	   
-	  4. This question anticipates a future topic, but what is the _joint_ distribution of $$p_1$$ and $$p_2$$? We have not formally defined the joint distribution yet, but this problem helps you appreciate the need for one.   
+	  4. This question anticipates a future topic, but what is the _joint_ distribution of $$L_1$$ and $$L_2$$? We have not formally defined the joint distribution yet, but this problem helps you appreciate the need for one.   
 
 
     We are handcalculating everything for now because we want to