diff --git a/source/exercises100.ktx b/source/exercises100.ktx
index 1840c420..232210d0 100644
--- a/source/exercises100.ktx
+++ b/source/exercises100.ktx
@@ -85,7 +85,7 @@ Create a 3x3 matrix with values ranging from 0 to 8 (★☆☆)
 hint: reshape
 
 < a9
-nz = np.nonzero([1,2,0,0,4,0])
+nz = np.arange(2, 11).reshape(3,3)
 print(nz)
 
 < q10