diff --git a/src/challenge.ts b/src/challenge.ts
index fad2280..3d1217d 100644
--- a/src/challenge.ts
+++ b/src/challenge.ts
@@ -19,8 +19,12 @@ import { Student } from "./students";
  */
 function getStudentsByCourse(students: Student[], course: string): Student[] {
   // write your code here...
+  // students.filter((s) => s.courses);
+  //const student  = students.filter((student) => {
+  //if(student.courses.forEach(x=>x === course))
 
-  return []; // replace empty array with what you see is fit
+  //});
+  return students; // replace empty array with what you see is fit
 }
 
 /**
diff --git a/src/students.ts b/src/students.ts
index ac9d6c0..ae7fe37 100644
--- a/src/students.ts
+++ b/src/students.ts
@@ -72,7 +72,7 @@ const students: Student[] = [
 function getStudentName(student: Student): string {
   // write your code here...
 
-  return ""; // replace empty string with what you see is fit
+  return `${student.name}`; // replace empty string with what you see is fit
 }
 
 /**
@@ -87,7 +87,7 @@ function getStudentName(student: Student): string {
 function getCourse(student: Student, courseIndex: number): string {
   // write your code here...
 
-  return ""; // replace empty string with what you see is fit
+  return `${student.courses[courseIndex]}`; // replace empty string with what you see is fit
 }
 
 /**
@@ -103,7 +103,7 @@ function getCourse(student: Student, courseIndex: number): string {
  */
 function addCourseToStudent(student: Student, course: string): Student {
   // write your code here...
-
+  student.courses.push(course);
   return student;
 }
 
@@ -117,7 +117,7 @@ function addCourseToStudent(student: Student, course: string): Student {
 function countCourses(student: Student): number {
   // write your code here...
 
-  return -1; // replace -1 with what you see is fit
+  return student.courses.length; // replace -1 with what you see is fit
 }
 
 /**
@@ -134,6 +134,11 @@ function countCourses(student: Student): number {
 function removeCourseFromStudent(student: Student, course: string): Student {
   // write your code here...
 
+  student.courses.forEach((item, index) => {
+    if (item === course) {
+      student.courses.splice(index, 1);
+    }
+  });
   return student;
 }
 
@@ -155,6 +160,8 @@ function findStudentById(
   studentId: number
 ): Student | undefined {
   // write your code here...
+  const studID = students.find((m) => m.id === studentId);
+  if (studID) return studID;
 
   return undefined; // replace undefined with what you see is fit
 }