diff --git a/README.md b/README.md
index debb56b..420634a 100644
--- a/README.md
+++ b/README.md
@@ -9,6 +9,21 @@ Create a function that receives an integers array and returns the number that ap
 | (1,1,2)         | 2        |
 | (2,2,1)         | 1        |
 
+answes :
+func retriveNum (aray: [Int]){
+    for i in 0..<aray.count{
+
+        if aray[i] == aray[i]+1 {
+        print ("array contain :\(aray[i] )")
+    }
+    else {
+        print ("array reapeat")
+    }
+    }
+    retriveNum(aray: [3,1,4])
+
+}
+
 
 ## 2nd Challenge
 Create a function that receives a string then it converts uppercase letters into lowercase and vice versa. The function then should print the converted value.
@@ -20,7 +35,20 @@ Create a function that receives a string then it converts uppercase letters into
 | Hello World    | hELLO wORLD    |
 | My name is Ali | mY NAME IS aLI |
 | sHroog         | ShROOG         |
+answers:
+func converletter (text: String){
+// text = text.lowercased()
 
+    if text.lowercased() == true{
+        text.uppercased()
+    }
+    else {
+        text.lowercased()
+    }
+
+print(converletter(text: "raz"))
+
+}
 
 ## 3rd Challenge
 Create a function that receives an array of items & arrays and returns one flattened array with all items exluding null values.
@@ -31,7 +59,20 @@ Create a function that receives an array of items & arrays and returns one flatt
 | 2 | [7, 0,[null],[null, null, 9]]         | [7, 0, 9]             |
 | 3 | [[null, 3], [2, 4, 5, null], 0, 8, 3] | [3, 2, 4, 5, 0, 8, 3] |
 | 4 | [3, 5, [5, 9, 0]]                     | [3, 5, 5, 9, 0]       |
-
+answers:
+func flatArray (){
+    var array = [[1,2,nil],[5,6,7,nil]]
+    var array2 = [Int]()
+    for i in 0..<array.count{
+        if array[i] == nil{
+            
+            print(array[i])
+            array.flatMap { array2 in
+                array.append(array2)
+            }
+        }
+    }
+}
 
 ## 4th Challenge
 Create a function that receives a string that contains combination of parentheses, square brackets, and curly braces. Then, it returns true if every opening bracket has a closing pair.
@@ -49,5 +90,17 @@ Create a function that receives a string that contains combination of parenthese
 | {[(}])   | true     |
 | {[}])    | false    |
 
+answers:
+func brac (text: String)-> Bool{
+    var check = false
+    if text.contains("}{"){
+        return false
+    }
+    else if  text.count % 2 != 0{
+        return false
+    }
+    return true
+}
+brac(text: "}{}")