diff --git a/gradlew b/gradlew
old mode 100755
new mode 100644
diff --git a/src/test/java/lambda/part1/exercise/Lambdas01Exercise.java b/src/test/java/lambda/part1/exercise/Lambdas01Exercise.java
index 14cfc0d..04b28c5 100644
--- a/src/test/java/lambda/part1/exercise/Lambdas01Exercise.java
+++ b/src/test/java/lambda/part1/exercise/Lambdas01Exercise.java
@@ -1,9 +1,14 @@
 package lambda.part1.exercise;
 
+import com.google.common.base.Optional;
+import com.google.common.base.Predicate;
+import com.google.common.collect.FluentIterable;
 import com.google.common.collect.ImmutableList;
 import data.Person;
 import org.junit.jupiter.api.Test;
 
+import java.util.Arrays;
+import java.util.Comparator;
 import java.util.List;
 
 import static org.junit.jupiter.api.Assertions.assertArrayEquals;
@@ -20,6 +25,12 @@ void sortPersonsByAge() {
         };
 
         // TODO use Arrays.sort
+        Arrays.sort(persons, new Comparator<Person>() {
+            @Override
+            public int compare(Person p1, Person p2) {
+                return Integer.compare(p1.getAge(), p2.getAge());
+            }
+        });
 
         assertArrayEquals(persons, new Person[]{
                 new Person("name 3", "lastName 3", 20),
@@ -39,6 +50,18 @@ void findFirstWithAge30() {
         Person person = null;
 
         // TODO use FluentIterable
+        Optional<Person> personOptional =
+                FluentIterable.from(persons)
+                .firstMatch(new Predicate<Person>() {
+                    @Override
+                    public boolean apply(Person p) {
+                        return p.getAge()==30;
+                    }
+                });
+
+
+        if (personOptional.isPresent())
+            person = personOptional.get();
 
         assertEquals(person, new Person("name 1", "lastName 2", 30));
     }
diff --git a/src/test/java/lambda/part1/exercise/Lambdas02Exercise.java b/src/test/java/lambda/part1/exercise/Lambdas02Exercise.java
index 8f47d34..f76abf5 100644
--- a/src/test/java/lambda/part1/exercise/Lambdas02Exercise.java
+++ b/src/test/java/lambda/part1/exercise/Lambdas02Exercise.java
@@ -1,9 +1,12 @@
 package lambda.part1.exercise;
 
+import com.google.common.base.Optional;
+import com.google.common.collect.FluentIterable;
 import com.google.common.collect.ImmutableList;
 import data.Person;
 import org.junit.jupiter.api.Test;
 
+import java.util.Arrays;
 import java.util.List;
 
 import static org.junit.jupiter.api.Assertions.assertArrayEquals;
@@ -19,6 +22,7 @@ void sortPersonsByAge() {
         };
 
         // TODO use Arrays.sort
+        Arrays.sort(persons, (o1, o2) -> Integer.compare(o1.getAge(), o2.getAge()));
 
         assertArrayEquals(persons, new Person[]{
                 new Person("name 3", "lastName 3", 20),
@@ -38,6 +42,12 @@ void findFirstWithAge30() {
         Person person = null;
 
         // TODO use FluentIterable
+        Optional<Person> personOptional = FluentIterable
+                .from(persons)
+                .firstMatch(p -> p.getAge() == 30);
+
+        if (personOptional.isPresent())
+            person = personOptional.get();
 
         assertEquals(person, new Person("name 1", "lastName 2", 30));
     }