diff --git a/project_euler/problem_01/sol1.py b/project_euler/problem_01/sol1.py
index e81156edaee4..0b3babccce19 100644
--- a/project_euler/problem_01/sol1.py
+++ b/project_euler/problem_01/sol1.py
@@ -6,8 +6,9 @@
 """
 
 
-def solution(n):
-    """Returns the sum of all the multiples of 3 or 5 below n.
+def solution(n: int = 10) -> int:
+    """
+    Returns the sum of all the multiples of 3 or 5 below n.
 
     >>> solution(3)
     0
@@ -25,4 +26,4 @@ def solution(n):
 
 
 if __name__ == "__main__":
-    print(solution(int(input().strip())))
+    print(solution(10))
diff --git a/project_euler/problem_01/sol2.py b/project_euler/problem_01/sol2.py
index 8041c7ffa589..26b75ad96c16 100644
--- a/project_euler/problem_01/sol2.py
+++ b/project_euler/problem_01/sol2.py
@@ -6,8 +6,9 @@
 """
 
 
-def solution(n):
-    """Returns the sum of all the multiples of 3 or 5 below n.
+def solution(n: int = 10) -> int:
+    """
+    Returns the sum of all the multiples of 3 or 5 below n.
 
     >>> solution(3)
     0
@@ -21,7 +22,9 @@ def solution(n):
 
     sum = 0
     terms = (n - 1) // 3
-    sum += ((terms) * (6 + (terms - 1) * 3)) // 2  # sum of an A.P.
+
+    # sum of an A.P.
+    sum += ((terms) * (6 + (terms - 1) * 3)) // 2
     terms = (n - 1) // 5
     sum += ((terms) * (10 + (terms - 1) * 5)) // 2
     terms = (n - 1) // 15
@@ -30,4 +33,4 @@ def solution(n):
 
 
 if __name__ == "__main__":
-    print(solution(int(input().strip())))
+    print(solution(10))
diff --git a/project_euler/problem_01/sol3.py b/project_euler/problem_01/sol3.py
index c0bcbc06ec83..ce93413152e3 100644
--- a/project_euler/problem_01/sol3.py
+++ b/project_euler/problem_01/sol3.py
@@ -6,7 +6,7 @@
 """
 
 
-def solution(n):
+def solution(n: int = 10) -> int:
     """
     This solution is based on the pattern that the successive numbers in the
     series follow: 0+3,+2,+1,+3,+1,+2,+3.
@@ -57,4 +57,4 @@ def solution(n):
 
 
 if __name__ == "__main__":
-    print(solution(int(input().strip())))
+    print(solution(10))
diff --git a/project_euler/problem_01/sol4.py b/project_euler/problem_01/sol4.py
index e01dc977d8cf..9032e782921a 100644
--- a/project_euler/problem_01/sol4.py
+++ b/project_euler/problem_01/sol4.py
@@ -6,8 +6,9 @@
 """
 
 
-def solution(n):
-    """Returns the sum of all the multiples of 3 or 5 below n.
+def solution(n: int = 10) -> int:
+    """
+    Returns the sum of all the multiples of 3 or 5 below n.
 
     >>> solution(3)
     0
@@ -44,4 +45,4 @@ def solution(n):
 
 
 if __name__ == "__main__":
-    print(solution(int(input().strip())))
+    print(solution(10))
diff --git a/project_euler/problem_01/sol5.py b/project_euler/problem_01/sol5.py
index bd96d965f92d..82e41de4bfe3 100644
--- a/project_euler/problem_01/sol5.py
+++ b/project_euler/problem_01/sol5.py
@@ -8,8 +8,9 @@
 """A straightforward pythonic solution using list comprehension"""
 
 
-def solution(n):
-    """Returns the sum of all the multiples of 3 or 5 below n.
+def solution(n: int = 10) -> int:
+    """
+    Returns the sum of all the multiples of 3 or 5 below n.
 
     >>> solution(3)
     0
@@ -25,4 +26,4 @@ def solution(n):
 
 
 if __name__ == "__main__":
-    print(solution(int(input().strip())))
+    print(solution(10))
diff --git a/project_euler/problem_01/sol6.py b/project_euler/problem_01/sol6.py
index c9f94b9f77c8..b46c162b0c2c 100644
--- a/project_euler/problem_01/sol6.py
+++ b/project_euler/problem_01/sol6.py
@@ -6,8 +6,9 @@
 """
 
 
-def solution(n):
-    """Returns the sum of all the multiples of 3 or 5 below n.
+def solution(n: int = 10) -> int:
+    """
+    Returns the sum of all the multiples of 3 or 5 below n.
 
     >>> solution(3)
     0
@@ -31,4 +32,4 @@ def solution(n):
 
 
 if __name__ == "__main__":
-    print(solution(int(input().strip())))
+    print(solution(10))
diff --git a/project_euler/problem_01/sol7.py b/project_euler/problem_01/sol7.py
index a0510b54c409..9475741375c6 100644
--- a/project_euler/problem_01/sol7.py
+++ b/project_euler/problem_01/sol7.py
@@ -6,8 +6,9 @@
 """
 
 
-def solution(n):
-    """Returns the sum of all the multiples of 3 or 5 below n.
+def solution(n: int = 10) -> int:
+    """
+    Returns the sum of all the multiples of 3 or 5 below n.
 
     >>> solution(3)
     0
@@ -29,4 +30,4 @@ def solution(n):
 
 
 if __name__ == "__main__":
-    print(solution(int(input().strip())))
+    print(solution(10))