errors in adding Admod in android studio in the layout file

I have this app, which was started from blank activity, unlike in the tutorial I am reading: https://developers.google.com/mobile-ads-sdk/docs/admob/android/quick-start

**1.**Is there a problem if I just started with the blank activity?

like in the tutorial, I added this peace of code to the build.gradle:

dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    compile 'com.android.support:appcompat-v7:21.0.0'
    compile 'com.google.android.gms:play-services:6.+'
}

Then, in the Manifest, I added this peaces of code:

    <!-- Include required permissions for Google Mobile Ads to run-->
        <uses-permission android:name="android.permission.INTERNET"/>
        <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>


<!--This meta-data tag is required to use Google Play Services.-->
        <meta-data android:name="com.google.android.gms.version"
        android:value="@integer/google_play_services_version" />


    <!--Include the AdActivity configChanges and theme. -->
                <activity android:name="com.google.android.gms.ads.AdActivity"
                android:configChanges="keyboard|keyboardHidden|orientation|screenLayout|uiMode|screenSize|smallestScreenSize"
                android:theme="@android:style/Theme.Translucent" />

Until now there are no problems. I created the "fragment_ad" in the layout folder, and replaced the default code with this(Like said in the tutorial):

<?xml version="1.0" encoding="utf-8"?>

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:ads="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <com.google.android.gms.ads.AdView
        android:id="@+id/adView"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_centerHorizontal="true"
        ads:adSize="BANNER"
        ads:adUnitId="@string/banner_ad_unit_id">
    </com.google.android.gms.ads.AdView>

</RelativeLayout>

...

In the tutorial, in step two(Create the AdFragment class), I noticed that I should have a PlaceHolderFragment class in my MainClass, so I pasted this code(Created another project, this time with blank activity and Fragment", went to the java file, and copied the clas below):

public static class PlaceholderFragment extends Fragment {
        public PlaceholderFragment() {
        }
        @Override
        public View onCreateView(LayoutInflater inflater, ViewGroup container,
                                 Bundle savedInstanceState) {
            View rootView = inflater.inflate(R.layout.fragment_ad, container, false);
            return rootView;
        }
    }

The next step is to go to the main activity layout, pasted the fragments below:

<fragment
    android:id="@+id/adFragment"
    android:name="com.google.android.gms.example.bannerexample.MainActivity$AdFragment"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_alignParentBottom="true" />

**2.**And here is the problem, i pasted those fragments and an error appears: "Cannot resolve symbol 'example'", on both of the "android:name="com.goo..."

Thanks for the help(There is still one more step after this problem is solved);