diff --git a/Work/bounce.py b/Work/bounce.py
index 3660ddd82..b609a0be0 100644
--- a/Work/bounce.py
+++ b/Work/bounce.py
@@ -1,3 +1,13 @@
 # bounce.py
 #
 # Exercise 1.5
+
+current_height = 100
+bounce_factor = 3 / 5
+bounce_number = 1
+
+
+while bounce_number <= 10:
+    current_height = current_height * bounce_factor
+    print(bounce_number, round(current_height, 4))
+    bounce_number += 1
diff --git a/Work/mortgage.py b/Work/mortgage.py
index d527314e3..35a1030f1 100644
--- a/Work/mortgage.py
+++ b/Work/mortgage.py
@@ -1,3 +1,29 @@
 # mortgage.py
 #
 # Exercise 1.7
+
+principal = 500000.0
+rate = 0.05
+payment = 2684.11
+extra_payment = 1000
+extra_payment_start_month = 61
+extra_payment_end_month = 108
+total_paid = 0.0
+month = 1
+
+while principal > 0:
+    if month <= extra_payment_end_month and month >= extra_payment_start_month:
+        monthly_payment = payment + extra_payment
+    else:
+        monthly_payment = payment
+    principal = principal * (1 + rate / 12)
+    if principal >= monthly_payment:
+        principal = principal - monthly_payment
+    else:
+        monthly_payment = principal
+        principal = 0
+    total_paid = total_paid + monthly_payment
+    print(month, total_paid, principal)
+    month += 1
+
+print("Total paid", total_paid)
diff --git a/Work/pcost.py b/Work/pcost.py
index e68aa20b4..65f90c298 100644
--- a/Work/pcost.py
+++ b/Work/pcost.py
@@ -1,3 +1,25 @@
 # pcost.py
 #
 # Exercise 1.27
+
+import os
+import csv
+
+
+def portfolio_cost(filename):
+    "returns total cost of the portfolio from filename"
+    total_cost = 0
+    with open(filename, "rt") as f:
+        rows = csv.reader(f)
+        next(rows)
+        for l in rows:
+            try:
+                [shares, price] = l[1:]
+                total_cost = total_cost + int(shares) * float(price)
+            except:
+                print("Could not parse:", l)
+    return total_cost
+
+
+total_cost = portfolio_cost("Data/missing.csv")
+print("Total cost:", total_cost)