[MultiQubitSystemMeasurements] Fix typo in the workbook (#844)

Co-authored-by: delight1019 <hyehyeon.kim@samsungmedison.com>

tutorials/MultiQubitSystemMeasurements/Workbook_MultiQubitSystemMeasurements.ipynb

@@ -359,8 +359,8 @@
    "source": [
     "### Solution\n",
     "\n",
-    "A measurement outcome of $0$ on the first qubit corresponds to the projection operator $P_0|0\\rangle\\langle 0| \\otimes \\mathbb{1}$. Applying it to the state $\\ket \\psi$ gives us \n",
-    "$$\\big|P_0 \\ket{\\psi}\\big|^2 = \\big|\\frac{1}{\\sqrt{10}} \\left(3\\ket {00} + \\ket{01}\\right) \\big|^2 = \\frac{5}{6}$$\n",
+    "A measurement outcome of $0$ on the first qubit corresponds to the projection operator $P_0 = |0\\rangle\\langle 0| \\otimes \\mathbb{1}$. Applying it to the state $\\ket \\psi$ gives us \n",
+    "$$\\big|P_0 \\ket{\\psi}\\big|^2 = \\big|\\frac{1}{\\sqrt{12}} \\left(3\\ket {00} + \\ket{01}\\right) \\big|^2 = \\frac{5}{6}$$\n",
     "and \n",
     "$$\\frac{P_0 \\ket{\\psi}}{\\big|P_0 \\ket{\\psi}\\big|} = \\frac{1}{\\sqrt{10}} \\left( 3\\ket{00} + \\ket{01}\\right)$$\n",
     "\n",