diff --git a/day21/excersises.py b/day21/excersises.py
new file mode 100644
index 0000000..af7b915
--- /dev/null
+++ b/day21/excersises.py
@@ -0,0 +1,150 @@
+
+# PT1
+
+ages = [31, 26, 34, 37, 27, 26, 32, 32, 26, 27, 27, 24, 32, 33, 27, 25, 26, 38, 37, 31, 34, 24, 33, 29, 26]
+
+class Estadisticas:
+    def __init__(self, items: list):
+        self.items = items
+
+    def count(self):
+        return len(self.items)
+    
+    def sum(self):
+        return sum(self.items)
+    
+    def min(self):
+        return min(self.items)
+    
+    def max(self):
+        return max(self.items)
+    
+    def range(self):
+        return max(self.items) - min(self.items)
+    
+    def mean(self):
+        return (sum(self.items) / len(self.items))
+    
+    def median(self):
+        return (sorted(self.items)[(len(self.items)//2)])
+    
+    def mode(self):
+        full_number = 0
+        full_mode = 0
+        sortedlist = sorted(self.items)
+        for i in range(len(sortedlist)):
+            current_number = sortedlist[i]
+            temp_mode = 0
+            for j in range(len(sortedlist)):
+                if sortedlist[j] == sortedlist[i]:
+                    temp_mode += 1
+            if temp_mode > full_mode:
+                full_number = current_number
+                full_mode = temp_mode
+        return {'mode': full_number, 'count': full_mode}
+    
+    def std(self):
+        new_list = []
+        mean = sum(self.items) / len(self.items)
+        for item in self.items:
+            new_list.append((item - mean) ** 2)
+        s = (sum(new_list)/(len(new_list))) ** (1/2)
+        return round(s,1)
+    
+    def var(self):
+        new_list = []
+        mean = sum(self.items) / len(self.items)
+        for item in self.items:
+            new_list.append((item - mean) ** 2)
+        return round(sum(new_list)/(len(new_list)),1)
+    
+    def freq_dist(self):
+        sortedlist = sorted(self.items)
+        new_list = []
+        current_number = 0
+        for i in range(len(sortedlist)):
+            if current_number != sortedlist[i]:
+                current_number = sortedlist[i]
+            current_count = 0
+            for j in range(len(sortedlist)):
+                if sortedlist[j] == sortedlist[i]:
+                    current_count += 1
+            if (current_number,current_count) not in new_list:
+                new_list.append((current_number,current_count))
+        return new_list
+    
+    def describe(self):
+        print('Count:', self.count()) # 25
+        print('Sum: ', self.sum()) # 744
+        print('Min: ', self.min()) # 24
+        print('Max: ', self.max()) # 38
+        print('Range: ', self.range()) # 14
+        print('Mean: ', self.mean()) # 30
+        print('Median: ', self.median()) # 29
+        print('Mode: ', self.mode()) # {'mode': 26, 'count': 5}
+        print('Standard Deviation: ', self.std()) # 4.2
+        print('Variance: ', self.var()) # 17.5
+        print('Frequency Distribution: ', self.freq_dist())
+
+data = Estadisticas(ages)
+
+data.describe()
+
+
+# PT 2
+
+
+"""
+Create a class called PersonAccount. It has firstname, lastname, incomes, expenses properties and it has total_income,
+total_expense, account_info, add_income, add_expense and account_balance methods. Incomes is a set of incomes and its
+description. The same goes for expenses.
+"""
+
+class CuentaPersona:
+    def __init__(self, prim_nom, apellido):
+        self.prim_nom = prim_nom
+        self.apellido = apellido
+        self.ingresos = set()
+        self.gastos   = set()
+
+    def gasto_total(self):
+        gastotot = 0
+        for item in list(self.gastos):
+            gasto, desc = item
+            gastotot += gasto
+
+        return gastotot 
+
+    def anadir_ingreso(self, monto: float, info: str):
+        self.ingresos.add((monto, info))
+
+    def anadir_gasto(self, monto: float, info: str):
+        self.gastos.add((monto, info))
+
+    def balance_cuenta(self):
+        lista = list(self.ingresos)
+        
+        suma1 = 0; suma2 = self.gasto_total()
+
+        for item in lista:
+            monto, desc = item
+            suma1 += monto
+
+        return suma1 - suma2
+
+        
+
+    def informacion_cuenta(self):
+        print(f"Nombre: {self.prim_nom} {self.apellido}")
+        print(f"Balance: {self.balance_cuenta()}")
+        print(f"Gastos: {self.gastos}")
+        print(f"Gasto Total {self.gasto_total()}")
+        print(f"Ingresos: {self.ingresos}")
+
+
+persona = CuentaPersona("Juan", "Ley")
+
+persona.anadir_gasto(29.30, "Coca de 2 litros")
+persona.anadir_ingreso(4900, "Pago")
+
+persona.informacion_cuenta()
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