diff --git a/src/test/java/lambda/part1/exercise/Lambdas01Exercise.java b/src/test/java/lambda/part1/exercise/Lambdas01Exercise.java
index 14cfc0d..2b87550 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 o1, Person o2) {
+                return o1.getAge()-o2.getAge();
+            }
+        });
 
         assertArrayEquals(persons, new Person[]{
                 new Person("name 3", "lastName 3", 20),
@@ -39,6 +50,14 @@ void findFirstWithAge30() {
         Person person = null;
 
         // TODO use FluentIterable
+        final Optional<Person> personOptional =
+                FluentIterable.from(persons)
+                        .firstMatch(new Predicate<Person>() {
+                            public boolean apply(Person p) {
+                                return p.getAge()==30;
+                            }
+                        });
+        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..fcf2f64 100644
--- a/src/test/java/lambda/part1/exercise/Lambdas02Exercise.java
+++ b/src/test/java/lambda/part1/exercise/Lambdas02Exercise.java
@@ -1,9 +1,13 @@
 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.Comparator;
 import java.util.List;
 
 import static org.junit.jupiter.api.Assertions.assertArrayEquals;
@@ -19,6 +23,9 @@ void sortPersonsByAge() {
         };
 
         // TODO use Arrays.sort
+        Arrays.sort(persons, (o1, o2) -> o1.getAge()-o2.getAge());
+//        Arrays.sort(persons, Comparator.comparing(p->p.getAge()));
+//        Arrays.sort(persons, Comparator.comparing(Person::getAge));
 
         assertArrayEquals(persons, new Person[]{
                 new Person("name 3", "lastName 3", 20),
@@ -38,6 +45,10 @@ void findFirstWithAge30() {
         Person person = null;
 
         // TODO use FluentIterable
+        final Optional<Person> personOptional =
+                FluentIterable.from(persons)
+                        .firstMatch(p -> p.getAge()==30);
+        person = personOptional.get();
 
         assertEquals(person, new Person("name 1", "lastName 2", 30));
     }