diff --git a/src/main/java/com/epam/izh/rd/online/repository/SimpleFileRepository.java b/src/main/java/com/epam/izh/rd/online/repository/SimpleFileRepository.java
index 1783b845..5fe76c90 100644
--- a/src/main/java/com/epam/izh/rd/online/repository/SimpleFileRepository.java
+++ b/src/main/java/com/epam/izh/rd/online/repository/SimpleFileRepository.java
@@ -1,5 +1,13 @@
 package com.epam.izh.rd.online.repository;
 
+import java.io.File;
+import java.io.FileReader;
+import java.io.IOException;
+import java.net.URL;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+
 public class SimpleFileRepository implements FileRepository {
 
     /**
@@ -10,7 +18,15 @@ public class SimpleFileRepository implements FileRepository {
      */
     @Override
     public long countFilesInDirectory(String path) {
-        return 0;
+        File[] files = new File("src/main/resources/" + path).listFiles();
+        long count = 0;
+        for (File file : files) {
+            if (file.isFile()) count++;
+            else {
+                count += countFilesInDirectory(path + "/" + file.getName());
+            }
+        }
+        return count;
     }
 
     /**
@@ -21,7 +37,14 @@ public long countFilesInDirectory(String path) {
      */
     @Override
     public long countDirsInDirectory(String path) {
-        return 0;
+        File[] files = new File("src/main/resources/" + path).listFiles();
+        long count = 1;
+        for (File file : files) {
+            if (file.isDirectory()) {
+                count += countDirsInDirectory(path + "/" + file.getName());
+            }
+        }
+        return count;
     }
 
     /**
@@ -32,7 +55,17 @@ public long countDirsInDirectory(String path) {
      */
     @Override
     public void copyTXTFiles(String from, String to) {
-        return;
+        File fileTo = new File(new File(to).getParent());
+        if (!fileTo.exists())fileTo.mkdir();
+        File[] files = new File(new File(from).getParent()).listFiles();
+        for (File file : files) {
+            if (file.isFile() && file.getName().endsWith(".txt")) {
+                try {
+                    Files.copy(file.toPath(), Paths.get(to));
+                } catch (IOException e) {
+                }
+            }
+        }
     }
 
     /**
@@ -44,6 +77,14 @@ public void copyTXTFiles(String from, String to) {
      */
     @Override
     public boolean createFile(String path, String name) {
+        File folder = new File(getClass().getResource("/").getPath() + "/" + path);
+        if (!folder.exists()) folder.mkdir();
+        File file = new File(folder.getPath() + "/" + name);
+        try {
+            return file.createNewFile();
+        } catch (IOException e) {
+            e.printStackTrace();
+        }
         return false;
     }
 
@@ -55,6 +96,16 @@ public boolean createFile(String path, String name) {
      */
     @Override
     public String readFileFromResources(String fileName) {
-        return null;
+        String str = "";
+        try (FileReader fileReader = new FileReader(new File("src/main/resources/" + fileName))) {
+            int c = 0;
+            while ((c=fileReader.read())!=-1){
+                str += String.valueOf((char) c);
+            }
+        } catch (IOException e) {
+            e.printStackTrace();
+        }
+
+        return str;
     }
 }
diff --git a/src/main/java/com/epam/izh/rd/online/service/SimpleBigNumbersService.java b/src/main/java/com/epam/izh/rd/online/service/SimpleBigNumbersService.java
index a94c7bba..b48b340c 100644
--- a/src/main/java/com/epam/izh/rd/online/service/SimpleBigNumbersService.java
+++ b/src/main/java/com/epam/izh/rd/online/service/SimpleBigNumbersService.java
@@ -2,6 +2,7 @@
 
 import java.math.BigDecimal;
 import java.math.BigInteger;
+import java.math.RoundingMode;
 
 public class SimpleBigNumbersService implements BigNumbersService {
 
@@ -13,7 +14,7 @@ public class SimpleBigNumbersService implements BigNumbersService {
      */
     @Override
     public BigDecimal getPrecisionNumber(int a, int b, int range) {
-        return null;
+        return new BigDecimal(a).divide(new BigDecimal(b),range, RoundingMode.HALF_UP);
     }
 
     /**
@@ -24,6 +25,10 @@ public BigDecimal getPrecisionNumber(int a, int b, int range) {
      */
     @Override
     public BigInteger getPrimaryNumber(int range) {
-        return null;
+        BigInteger integer = new BigInteger("2");
+        for (int i = 0; i < range; i++) {
+            integer = integer.nextProbablePrime();
+        }
+        return integer;
     }
 }
diff --git a/src/main/java/com/epam/izh/rd/online/service/SimpleDateService.java b/src/main/java/com/epam/izh/rd/online/service/SimpleDateService.java
index 70d64dfd..891e044a 100644
--- a/src/main/java/com/epam/izh/rd/online/service/SimpleDateService.java
+++ b/src/main/java/com/epam/izh/rd/online/service/SimpleDateService.java
@@ -2,7 +2,9 @@
 
 import java.time.LocalDate;
 import java.time.LocalDateTime;
+import java.time.Year;
 import java.time.format.DateTimeFormatter;
+import java.util.Calendar;
 
 public class SimpleDateService implements DateService {
 
@@ -14,7 +16,8 @@ public class SimpleDateService implements DateService {
      */
     @Override
     public String parseDate(LocalDate localDate) {
-        return null;
+        DateTimeFormatter formatter = DateTimeFormatter.ofPattern("dd-MM-yyyy");
+        return localDate.format(formatter);
     }
 
     /**
@@ -25,7 +28,8 @@ public String parseDate(LocalDate localDate) {
      */
     @Override
     public LocalDateTime parseString(String string) {
-        return null;
+        DateTimeFormatter format = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm");
+        return LocalDateTime.parse(string,format);
     }
 
     /**
@@ -37,7 +41,7 @@ public LocalDateTime parseString(String string) {
      */
     @Override
     public String convertToCustomFormat(LocalDate localDate, DateTimeFormatter formatter) {
-        return null;
+        return localDate.format(formatter);
     }
 
     /**
@@ -47,7 +51,11 @@ public String convertToCustomFormat(LocalDate localDate, DateTimeFormatter forma
      */
     @Override
     public long getNextLeapYear() {
-        return 0;
+        int year = Calendar.getInstance().get(Calendar.YEAR) + 1;
+        while (!Year.isLeap(year)) {
+            year++;
+        }
+        return year;
     }
 
     /**
@@ -57,7 +65,9 @@ public long getNextLeapYear() {
      */
     @Override
     public long getSecondsInYear(int year) {
-        return 0;
+        int day = 365;
+        if (Year.of(year).isLeap()) day = 366;
+        return day*24*60*60;
     }
 
 
diff --git a/src/main/java/com/epam/izh/rd/online/service/SimpleRegExpService.java b/src/main/java/com/epam/izh/rd/online/service/SimpleRegExpService.java
index b6eff56b..89c4d640 100644
--- a/src/main/java/com/epam/izh/rd/online/service/SimpleRegExpService.java
+++ b/src/main/java/com/epam/izh/rd/online/service/SimpleRegExpService.java
@@ -1,5 +1,10 @@
 package com.epam.izh.rd.online.service;
 
+import java.io.BufferedReader;
+import java.io.File;
+import java.io.FileReader;
+import java.io.IOException;
+
 public class SimpleRegExpService implements RegExpService {
 
     /**
@@ -11,7 +16,17 @@ public class SimpleRegExpService implements RegExpService {
      */
     @Override
     public String maskSensitiveData() {
-        return null;
+        String regex = "(\\d+)(\\s\\d+)(\\s\\d+)\\s(\\d+)";
+        String replacement = "$1 **** **** $4";
+        String str = "";
+        try {
+            BufferedReader reader = new BufferedReader( new FileReader(
+                    new File("src/main/resources/sensitive_data.txt")));
+            str = reader.readLine();
+        } catch (IOException e) {
+            e.printStackTrace();
+        }
+        return str.replaceAll(regex,replacement);
     }
 
     /**
@@ -22,6 +37,18 @@ public String maskSensitiveData() {
      */
     @Override
     public String replacePlaceholders(double paymentAmount, double balance) {
-        return null;
+        String regex1 = "${payment_amount}";
+        String regex2 = "${balance}";
+        String str = "";
+        try {
+            BufferedReader reader = new BufferedReader( new FileReader(
+                    new File("src/main/resources/sensitive_data.txt")));
+            str = reader.readLine();
+            str = str.replace(regex1,String.valueOf( (int) paymentAmount));
+            str = str.replace(regex2,String.valueOf( (int) balance));
+        } catch (IOException e) {
+            e.printStackTrace();
+        }
+        return str;
     }
 }
diff --git a/src/main/java/com/epam/izh/rd/online/service/SimpleTextService.java b/src/main/java/com/epam/izh/rd/online/service/SimpleTextService.java
index 68951fbe..b14088c7 100644
--- a/src/main/java/com/epam/izh/rd/online/service/SimpleTextService.java
+++ b/src/main/java/com/epam/izh/rd/online/service/SimpleTextService.java
@@ -13,7 +13,7 @@ public class SimpleTextService implements TextService {
      */
     @Override
     public String removeString(String base, String remove) {
-        return null; //TODO
+        return base.replaceAll(remove,""); //TODO
     }
 
     /**
@@ -24,7 +24,8 @@ public String removeString(String base, String remove) {
      */
     @Override
     public boolean isQuestionString(String text) {
-        return false; //TODO
+        if (text.endsWith("?")) return true;
+        else return false; //TODO
     }
 
     /**
@@ -35,7 +36,11 @@ public boolean isQuestionString(String text) {
      */
     @Override
     public String concatenate(String... elements) {
-        return null; //TODO
+        String result = "";
+        for (String element : elements) {
+            result += element;
+        }
+        return result; //TODO
     }
 
     /**
@@ -47,7 +52,11 @@ public String concatenate(String... elements) {
      */
     @Override
     public String toJumpCase(String text) {
-        return null; //TODO
+        char[] chars = text.toLowerCase().toCharArray();
+        for (int i = 1; i < chars.length; i += 2) {
+            chars[i] = Character.toUpperCase(chars[i]);
+        }
+        return new String(chars); //TODO
     }
 
     /**
@@ -59,6 +68,15 @@ public String toJumpCase(String text) {
      */
     @Override
     public boolean isPalindrome(String string) {
-       return false; //TODO
+        string = string.toLowerCase().replaceAll(" ","");
+        char[] chars = string.toCharArray();
+        int count = 0;
+        for (int i = 0, j = chars.length - 1; i < chars.length;j--, i++) {
+            if (chars[i] == chars[j]) {
+                count++;
+            }
+        }
+        if (count == 0) return false;
+        return count==chars.length; //TODO
     }
 }