diff --git a/experiment/theory.md b/experiment/theory.md
index 637fcf3..2671c0a 100644
--- a/experiment/theory.md
+++ b/experiment/theory.md
@@ -26,10 +26,10 @@ Let us assume that a 3-bit message is to be transmitted with an even parity bit.
 
   **Fig. 2: Circuit diagram of even parity generator.**</center>
 
-
+<center>
   **Table 1: Truth table of even parity generator**
 
-  <table style="text-align:center;color:black;margin-left: auto;margin-right: auto;">
+  <table style="text-align:center;color:black;margin-left:auto;margin-right:auto;">
        <tr style="border:1px solid black;font-size:130%;border-collapse:collapse;">
       <th colspan="3"; style="border:1px solid black;border-collapse:collapse;width:110px;text-align:center;">3-bit message</th>
       <th style="border:1px solid black;border-collapse:collapse;width:110px;text-align:center;" >Parity bit</th>
@@ -89,7 +89,7 @@ Let us assume that a 3-bit message is to be transmitted with an even parity bit.
       <td style="border:1px solid black;font-size:110%;border-collapse:collapse;">1</td>
       </tr>
   </table>
-
+</center>