fixed example in 4c

ML_lab1_review_student.ipynb

@@ -26,7 +26,7 @@
    },
    "outputs": [],
    "source": [
-    "labVersion = 'cs190_week1_v_1_1'"
+    "labVersion = 'cs190_week1_v_1_2'"
    ]
   },
   {
@@ -652,7 +652,7 @@
    "source": [
     "#### ** (4c) Lambda expression arguments **\n",
     "#### Lambda expressions can be used to generate functions that take in zero or more parameters.  The syntax for `lambda` allows for multiple ways to define the same function.  For example, we might want to create a function that takes in a single parameter, where the parameter is a tuple consisting of two values, and the function adds the two values together.  The syntax could be either: `lambda x: x[0] + x[1]` or `lambda (x0, x1): x0 + x1`.  If we called either function on the tuple `(3, 4)` it would return `7`.  Note that the second `lambda` relies on the tuple `(3, 4)` being unpacked automatically, which means that `x0` is assigned the value `3` and `x1` is assigned the value `4`.\n",
-    "#### As an other example, consider the following parameter lambda expressions: `lambda x, y: (x[0] + y[0], x[1] + y[1])` and `lambda (x0, x1), (y0, y1): (x0 + x1, y0 + y1)`.  The result of applying either of these functions to tuples  `(1, 2)` and `(3, 4)` would be the tuple `(4, 6)`.\n",
+    "#### As an other example, consider the following parameter lambda expressions: `lambda x, y: (x[0] + y[0], x[1] + y[1])` and `lambda (x0, x1), (y0, y1): (x0 + y0, x1 + y1)`.  The result of applying either of these functions to tuples  `(1, 2)` and `(3, 4)` would be the tuple `(4, 6)`.\n",
     "#### For this exercise: you'll create one-parameter functions `swap1` and `swap2` that swap the order of a tuple; a one-parameter function `swapOrder` that takes in a tuple with three values and changes the order to: second element, third element, first element; and finally, a three-parameter function `sumThree` that takes in three tuples, each with two values, and returns a tuple containing two values: the sum of the first element of each tuple and the sum of second element of each tuple."
    ]
   },
@@ -674,9 +674,9 @@
     "\n",
     "# Two-parameter function\n",
     "b1 = lambda x, y: (x[0] + y[0], x[1] + y[1])\n",
-    "b2 = lambda (x0, x1), (y0, y1): (x0 + x1, y0 + y1)\n",
+    "b2 = lambda (x0, x1), (y0, y1): (x0 + y0, x1 + y1)\n",
     "print '\\nb1( (1,2), (3,4) ) = {0}'.format( b1( (1,2), (3,4) ) )\n",
-    "print 'b2( (1,2), (3,4) ) = {0}'.format( b1( (1,2), (3,4) ) )"
+    "print 'b2( (1,2), (3,4) ) = {0}'.format( b2( (1,2), (3,4) ) )"
    ]
   },
   {