Update tutorial.md

doc/python/tutorial.md

@@ -88,7 +88,7 @@ In default, `NDArray` performs elemental-wise operations:
 ```python
 >>> a = mx.nd.ones((2, 3)) * 2
 >>> b = mx.nd.ones((2, 3)) * 4
->>> print a.asnumpy()
+>>> print b.asnumpy()
 [[ 4.  4.  4.]
  [ 4.  4.  4.]]
 >>> c = a + b
@@ -419,7 +419,7 @@ control how data is merged.
 >>> def update(key, input, stored):
 >>>     print "update on key: %d" % key
 >>>     stored += input * 2
->>> kv.set_updater(update)
+>>> kv._set_updater(update)
 >>> kv.pull(3, out=a)
 >>> print a.asnumpy()
 [[ 4.  4.  4.]