diff --git a/luku06.tex b/luku06.tex
index 6ee8f82..e4cb004 100644
--- a/luku06.tex
+++ b/luku06.tex
@@ -102,7 +102,7 @@ if the coins are $\{1,3,4\}$ and the target sum
 is 6, the greedy algorithm produces the solution
 $4+1+1$ while the optimal solution is $3+3$.
 
-We do not know if the general coin problem
+It is not known if the general coin problem
 can be solved using any greedy algorithm.
 However, as we will see in Chapter 7,
 the general problem can be efficiently