diff --git a/lyx.10.md b/lyx.10.md
new file mode 100644
index 0000000..be49cca
--- /dev/null
+++ b/lyx.10.md
@@ -0,0 +1,23 @@
+void AsSortbyNum(STU stu[], int n, int m)
+{
+    int  i, j, k, t;
+    for (i=0; i<n-1; i++)
+    {
+        k = i;
+        for (j=i+1; j<n; j++)
+        {
+            if (stu[j].num < stu[k].num)    k = j;
+        }
+        if (k != i)
+        {
+            for (t=0; t<m; t++)          
+              {
+                   SwapFloat(&stu[k].score[t], &stu[i].score[t]);
+            }
+SwapFloat(&stu[k].sum, &stu[i].sum);  
+SwapFloat(&stu[k].aver, &stu[i].aver);   
+SwapLong(&stu[k].num, &stu[i].num);     
+SwapChar(stu[k].name, stu[i].name);  
+        }
+    }
+}
diff --git a/lyx.md b/lyx.md
new file mode 100644
index 0000000..b5e381e
--- /dev/null
+++ b/lyx.md
@@ -0,0 +1,16 @@
+void AverSumofEveryStudent(STU stu[], int n, int m)
+{
+	int i, j;
+	for (i=0; i<n; i++)
+	{
+	    stu[i].sum = 0;
+	    for (j=0; j<m; j++)
+	    {
+            stu[i].sum = stu[i].sum + stu[i].score[j];
+	    }
+	    stu[i].aver = m>0 ? stu[i].sum / m : -1;
+	    printf("student %d: sum = %.0f, aver = %.0f\n", 
+i+1, stu[i].sum, stu[i].aver);
+	}	
+}
+
diff --git a/lyx16.md b/lyx16.md
new file mode 100644
index 0000000..3a28f73
--- /dev/null
+++ b/lyx16.md
@@ -0,0 +1,27 @@
+
+void StatisticAnalysis(STU stu[], int n, int m)
+{
+	int  i, j, t[6];
+	for (j=0; j<m; j++)
+	{
+		printf("For course %d:\n", j+1);
+	     memset(t, 0, sizeof(t)); 
+		for (i=0; i<n; i++)
+		{
+			if (stu[i].score[j]>=0 && stu[i].score[j]<60)t[0]++;
+			else if (stu[i].score[j]<70)				   t[1]++;
+			else if (stu[i].score[j]<80)				   t[2]++;
+			else if (stu[i].score[j]<90)				   t[3]++;
+			else if (stu[i].score[j]<100)				   t[4]++;
+			else if (stu[i].score[j] == 100)      		   t[5]++;
+		}
+		for (i=0; i<=5; i++)
+		{
+            if (i==0) printf("<60\t%d\t%.2f%%\n",t[i],(float)t[i]/n*100);
+	       else if (i==5) printf("%d\t%d\t%.2f%%\n",
+(i+5)*10,t[i],(float)t[i]/n*100);
+	       else 	printf("%d-%d\t%d\t%.2f%%\n", 
+(i+5)*10, (i+5)*10+9, t[i], (float)t[i]/n*100);	
+		}
+	}
+}
\ No newline at end of file
diff --git a/lyx6.md b/lyx6.md
new file mode 100644
index 0000000..87e453a
--- /dev/null
+++ b/lyx6.md
@@ -0,0 +1,4 @@
+int Descending(float a, float b)
+{
+	return a > b;
+    }
\ No newline at end of file