diff --git a/subjects/blood_types/README.md b/subjects/blood_types/README.md
index 5aba94f1..061abb96 100644
--- a/subjects/blood_types/README.md
+++ b/subjects/blood_types/README.md
@@ -2,12 +2,12 @@
 
 ### Instructions
 
-In this exercise you will create a model data model of blood types and an API to deal with blood types
+In this exercise you will create a data model of blood types and an API to deal with blood types
 
-Start by creating the data representation of the blood types:
+Start by copying the data representation of the blood types:
 - Create the enumerator `Antigen` that has 4 possibilities: A, B, O and AB And the enumerator `RhFactor` that has two possible values: Positive and Negative
 
-- After, create the struct BloodType that contains two fields with the names antigen and rh_factor
+- After, copy the struct BloodType that contains two fields with the names antigen and rh_factor
 
 - To provide a simple way to create blood types implement the trait FromStr for BloodType (which will allow us to use the `parse` method and the associated function from_str, so we can do:
 
@@ -19,11 +19,11 @@ Start by creating the data representation of the blood types:
 
 - Implement the trait std::Debug for BloodType allowing to print a vector such as [BloodType { antigen: A, rh_factor: Positive}, BloodType{ antigen: B, rh_factor: Negative}] as [ A+, A-] using the formatting {:?}
 
-Write three methods for BloodType:
+- Lastly, write three methods for BloodType:
 
-- `can_receive_from`: which returns true if self can receive blood from `other` blood type
-- `donors`: which returns all the blood types that can give blood to self
-- `recipients`: which returns all the blood types that can receive blood from self
+  - `can_receive_from`: which returns true if `self` can receive blood from `other` blood type
+  - `donors`: which returns all the blood types that can give blood to `self`
+  - `recipients`: which returns all the blood types that can receive blood from `self`
 
 ### Expected Functions and Structures
 
diff --git a/subjects/blood_types_s/README.md b/subjects/blood_types_s/README.md
new file mode 100644
index 00000000..9fe00071
--- /dev/null
+++ b/subjects/blood_types_s/README.md
@@ -0,0 +1,92 @@
+## blood_types_s
+
+### Instructions
+
+Use the following table to define the methods asked:
+
+| Blood Types | Donate Blood to  | Receive Blood From |
+|-------------|------------------|--------------------|
+| A+          | A+, AB+          | A+, A-, O+, O-     |
+| O+          | O+, A+, B+, AB+  | O+, O-             |
+| B+          | O+, O-           | B+, B-, O+, O-     |
+| AB+         | AB+              | Everyone           |
+| A-          | A+, A-, AB+, AB- | A-, O-             |
+| O-          | Everyone         | O-                 |
+| B-          | B+, B-, AB+, AB- | B-, O-             |
+| AB-         | AB+, AB-         | AB-, A-, B-, O-    |
+
+Write three methods for BloodType:
+
+- `can_receive_from`: which returns true if `self` can receive blood from `other` blood type
+- `donors`: which returns all the blood types that can give blood to `self`
+- `recipients`: which returns all the blood types that can receive blood from `self`
+
+### Expected Functions and Structures
+
+```rust
+#[derive(Debug, PartialEq, Eq, Clone, PartialOrd, Ord)]
+pub enum Antigen {
+	A,
+	AB,
+	B,
+	O,
+}
+
+#[derive(Debug, PartialEq, Eq, PartialOrd, Ord, Clone)]
+enum RhFactor {
+	Positive,
+	Negative,
+}
+
+#[derive(PartialEq, Eq, PartialOrd, Ord, Clone)]
+pub struct BloodType {
+	pub antigen: Antigen,
+	pub rh_factor: RhFactor,
+}
+
+impl BloodType {
+	pub fn can_receive_from(&self, other: &Self) -> bool {
+	}
+
+	pub fn donors(&self) -> Vec<Self> {
+	}
+
+	pub fn recipients(&self) -> Vec<Self> {
+}
+```
+
+### Usage
+
+Here is a program to test your function.
+
+```rust
+use blood_types_s::{Antigen, BloodType, RhFactor};
+
+fn main() {
+	let blood_type = BloodType {
+		antigen: Antigen::O,
+		rh_factor: RhFactor::Positive,
+	};
+	println!("recipients of O+ {:?}", blood_type.recipients());
+	println!("donors of O+ {:?}", blood_type.donors());
+	let another_blood_type = BloodType {
+		antigen: Antigen::O,
+		rh_factor: RhFactor::Positive,
+	};
+	println!(
+		"donors of O+ can receive from {:?} {:?}",
+		&another_blood_type,
+		blood_type.can_receive_from(&another_blood_type)
+	);
+}
+```
+
+And its output
+
+```console
+student@ubuntu:~/[[ROOT]]/test$ cargo run
+recipients of O+ [BloodType { antigen: AB, rh_factor: Positive }, BloodType { antigen: O, rh_factor: Positive }, BloodType { antigen: A, rh_factor: Positive }, BloodType { antigen: B, rh_factor: Positive }]
+donors of O+ [BloodType { antigen: O, rh_factor: Positive }, BloodType { antigen: O, rh_factor: Negative }]
+donors of O+ can receive from BloodType { antigen: O, rh_factor: Positive } true
+student@ubuntu:~/[[ROOT]]/test$
+```
diff --git a/subjects/display_table/README.md b/subjects/display_table/README.md
new file mode 100644
index 00000000..31419c7f
--- /dev/null
+++ b/subjects/display_table/README.md
@@ -0,0 +1,79 @@
+## display_table
+
+### Instructions
+
+- Implement the std::fmt::Display trait for the structure table so the table is printed like in the [Usage](#usage) the length of each column must adjust to the longest element of the column and the element must be centered in the "cell" when possible, if the length of the element doesn't allow to center exactly it must alight slightly to the right.
+
+  - Note: If the table is empty `println!` must not print anything.
+
+- Define the associated function `new` that create a new empty table.
+
+- Define the method function `add_row` that adds a new row to the table created from a slice of strings.
+
+### Expected function
+
+```rust
+pub struct Table {
+	pub headers: Vec<String>,
+	pub body: Vec<Vec<String>>,
+}
+
+impl fmt::Display for Table {
+}
+
+impl Table {
+	pub fn new() -> Table {
+	}
+
+	pub fn add_row(&mut self, row: &[String]) {
+	}
+}
+```
+
+### Usage
+
+Here is a possible test for your function:
+
+```rust
+fn main() {
+	let mut table = Table::new();
+	println!("{}", table);
+	table.headers = vec![
+		String::from("Model"),
+		String::from("Piece N°"),
+		String::from("In Stock"),
+		String::from("Description"),
+	];
+	table.add_row(&[
+		String::from("model 1"),
+		String::from("43-EWQE304"),
+		String::from("30"),
+		String::from("Piece for x"),
+	]);
+	table.add_row(&[
+		String::from("model 2"),
+		String::from("98-QCVX5433"),
+		String::from("100000000"),
+		String::from("-"),
+	]);
+	table.add_row(&[
+		String::from("model y"),
+		String::from("78-NMNH"),
+		String::from("60"),
+		String::from("nothing"),
+	]);
+	println!("{}", table);
+}
+```
+
+And its output:
+
+```console
+student@ubuntu:~/[[ROOT]]/test$ cargo run
+|  Model  |  Piece N°   | In Stock  | Description |
+|---------+-------------+-----------+-------------|
+| model 1 | 43-EWQE304  |    30     | Piece for x |
+| model 2 | 98-QCVX5433 | 100000000 |      -      |
+| model y |   78-NMNH   |    60     |   nothing   |
+student@ubuntu:~/[[ROOT]]/test$
+```
diff --git a/subjects/filter_table/README.md b/subjects/filter_table/README.md
new file mode 100644
index 00000000..f33ce790
--- /dev/null
+++ b/subjects/filter_table/README.md
@@ -0,0 +1,85 @@
+## filter_table
+
+### Instructions
+
+- Define the functions:
+
+  - new: creates a new empty table.
+
+  - add_rows: adds a new row to the table from a slice of strings.
+  
+  - filter_cols: that receives a closure that receives a `&str` and returns a `bool` value:
+
+	- filter_cols returns a table with all the columns that yielded true when applied to the header.
+  
+  - filter_rows: that receives a closure that receives a `&str` and returns a `bool` value
+
+	- filter_rows returns a table with all the columns that yielded true when applied to the elements of the selected column.
+
+### Expected function
+
+```rust
+pub struct Table {
+	pub headers: Vec<String>,
+	pub body: Vec<Vec<String>>,
+}
+
+impl Table {
+	pub fn new() -> Table {
+	}
+
+	pub fn add_row(&mut self, row: &[String]) {
+	}
+
+	pub fn filter_col(&self, filter: ) -> Option<Self> {
+
+	}
+
+	pub fn filter_row(&self, col_name: &str, filter: ) -> Option<Self> {
+	}
+}
+```
+
+### Usage
+
+Here is a possible test for your function:
+
+```rust
+fn main() {
+	let mut table = Table::new();
+	table.headers = vec![
+		"Name".to_string(),
+		"Last Name".to_string(),
+		"ID Number".to_string(),
+	];
+	table.add_row(&[
+		"Adam".to_string(),
+		"Philips".to_string(),
+		"123456789".to_string(),
+	]);
+	table.add_row(&[
+		"Adamaris".to_string(),
+		"Shelby".to_string(),
+		"1111123456789".to_string(),
+	]);
+	table.add_row(&[
+		"Ackerley".to_string(),
+		"Philips".to_string(),
+		"123456789".to_string(),
+	]);
+	let filter_names = |col: &str| col == "Name";
+	println!("{:?}", table.filter_col(filter_names));
+
+	let filter_philips = |lastname: &str| lastname == "Philips";
+	println!("{:?}", table.filter_row("Last Name", filter_philips));
+}
+```
+
+And its output:
+
+```console
+student@ubuntu:~/[[ROOT]]/test$ cargo run
+Some(Table { headers: ["Name"], body: [["Adam"], ["Adamaris"], ["Ackerley"]] })
+Some(Table { headers: ["Name", "Last Name", "ID Number"], body: [["Adam", "Philips", "123456789"], ["Ackerley", "Philips", "123456789"]] })
+student@ubuntu:~/[[ROOT]]/test$
+```
diff --git a/subjects/flat_tree/README.md b/subjects/flat_tree/README.md
new file mode 100644
index 00000000..3ecda4c6
--- /dev/null
+++ b/subjects/flat_tree/README.md
@@ -0,0 +1,43 @@
+## flat_rust
+
+### Instructions
+
+- Define the functions `flatten_tree` that receives a std::collections::BTreeSet and returns a new `Vec` with the elements in the binary tree in order.
+
+### Expected function
+
+```rust
+pub fn flatten_tree<T: ToOwned<Owned = T>>(tree: &BTreeSet<T>) -> Vec<T> {
+}
+```
+
+### Usage
+
+Here is a possible test for your function:
+
+```rust
+fn main() {
+	let mut tree = BTreeSet::new();
+	tree.insert(34);
+	tree.insert(0);
+	tree.insert(9);
+	tree.insert(30);
+	println!("{:?}", flatten_tree(&tree));
+
+	let mut tree = BTreeSet::new();
+	tree.insert("Slow");
+	tree.insert("kill");
+	tree.insert("will");
+	tree.insert("Horses");
+	println!("{:?}", flatten_tree(&tree));
+}
+```
+
+And its output:
+
+```console
+student@ubuntu:~/[[ROOT]]/test$ cargo run
+[0, 9, 30, 34]
+["Horses", "Slow", "kill", "will"]
+student@ubuntu:~/[[ROOT]]/test$
+```
diff --git a/subjects/insertion_sort/Insertion-Sort-demo.jpg b/subjects/insertion_sort/Insertion-Sort-demo.jpg
new file mode 100644
index 00000000..cbe8848f
Binary files /dev/null and b/subjects/insertion_sort/Insertion-Sort-demo.jpg differ
diff --git a/subjects/insertion_sort/README.md b/subjects/insertion_sort/README.md
new file mode 100644
index 00000000..550ec737
--- /dev/null
+++ b/subjects/insertion_sort/README.md
@@ -0,0 +1,56 @@
+## insertion_sort
+
+### Instructions
+
+The insertion sort algorithm:
+
+- To sort an array of size n in ascending order:
+
+1. Iterate from slice[1] to slice[n] over the slice.
+
+2. Compare the current element (key) to its predecessor.
+
+3. If the key element is smaller than its predecessor, compare it to the elements before. Move the greater elements one position up to make space for the swapped element.
+
+Here is a visual example of sorting a slice step by step using the insertion sort algorithm.
+
+![](Insertion-Sort-demo.jpg)
+**Figure 1** - Step by step execution of the algorithm insertion sort
+
+- Implement the algorithm insertion sort by creating a function `insertion_sort(slice, steps)` that executes the iterations of the algorithm the number of steps indicated by the parameter `steps`. See the [Usage](#usage) for more information.
+
+### Expected Function
+
+```rust
+pub fn insertion_sort(slice: &mut [i32], steps: usize) {
+}
+```
+
+### Usage
+
+Here is a possible program to test your function
+
+```rust
+fn main() {
+	let mut target = [5, 3, 7, 2, 1, 6, 8, 4];
+	// executes the first iteration of the algorithm
+	insertion_sort(&mut target, 1);
+	println!("{:?}", target);
+
+	let mut target = [5, 3, 7, 2, 1, 6, 8, 4];
+	let len = target.len();
+	// executes len - 1 iterations of the algorithm
+	// i.e. sorts the slice
+	insertion_sort(&mut target, len - 1);
+	println!("{:?}", target);
+}
+```
+
+And it's output:
+
+```console
+student@ubuntu:~/[[ROOT]]/test$ cargo run
+[3, 5, 7, 2, 1, 6, 8, 4]
+[1, 2, 3, 4, 5, 6, 7, 8]
+student@ubuntu:~/[[ROOT]]/test$
+```
diff --git a/subjects/matrix_display/README.md b/subjects/matrix_display/README.md
new file mode 100644
index 00000000..d5acc795
--- /dev/null
+++ b/subjects/matrix_display/README.md
@@ -0,0 +1,44 @@
+## matrix_display
+
+### Instructions
+
+Use the Matrix struct given in the [expected struct](#expected-functions-and-struct) and implement the `std::fmt::Display` trait so it prints the matrix like in the [usage](#usage).
+
+You will also have to implement the associated function `new` that creates a matrix from a slice of slices.
+
+### Expected Functions and Struct
+
+```rust
+pub struct Matrix(pub Vec<Vec<i32>>);
+
+pub fn new(slice: &[&[i32]]) -> Self {
+}
+
+use std::fmt;
+
+impl fmt::Display for Matrix {
+}
+```
+
+### Usage
+
+Here is a possible program to test your function
+
+```rust
+use matrix_display::*;
+
+fn main() {
+	let matrix = Matrix::new(&[&[1, 2, 3], &[4, 5, 6], &[7, 8, 9]]);
+	println!("{}", matrix);
+}
+```
+
+And it's output:
+
+```console
+student@ubuntu:~/[[ROOT]]/test$ cargo run
+(1 2 3)
+(4 5 6)
+(7 8 9)
+student@ubuntu:~/[[ROOT]]/test$
+```
diff --git a/subjects/matrix_transposition/README.md b/subjects/matrix_transposition/README.md
index eaae796f..a1d479fe 100644
--- a/subjects/matrix_transposition/README.md
+++ b/subjects/matrix_transposition/README.md
@@ -13,7 +13,7 @@
 Example:
 
 ```
-( a b )     __ transposition __> ( a d )
+( a b )   __ transposition __>   ( a d )
 ( c d )                          ( b d )
 ```
 
diff --git a/subjects/matrix_transposition_4by3/README.md b/subjects/matrix_transposition_4by3/README.md
new file mode 100644
index 00000000..812e5b35
--- /dev/null
+++ b/subjects/matrix_transposition_4by3/README.md
@@ -0,0 +1,69 @@
+## matrix_transposition_4by3
+
+### Instructions
+
+- Define the structure matrix as a tuple of tuples of `i32`'s
+
+- Define a function that calculate the transpose matrix of a 4x3 matrix (4 rows by 3 columns) which is a 3x4 matrix (3 rows by 4 columns).
+
+- Note:
+
+	- The transpose of a matrix `A` is the matrix `A'` where `A'`'s columns are `A`'s row and the rows are the columns:
+
+Example:
+
+```
+( a b c )   __ transposition __>   ( a d g j )
+( d e f )                          ( b e h k )
+( g h i )                          ( c f i l )
+( j k l )
+```
+
+- Matrix must implement Debug, PartialEq and Eq. You can use derive
+
+- Remember that you're defining a library so you have to make public the elements that are going to be called from an external crate.
+
+### Notions
+
+[Chapter 7]( https://doc.rust-lang.org/stable/book/ch07-03-paths-for-referring-to-an-item-in-the-module-tree.html )
+
+### Expected Function and Structs
+
+```rust
+pub struct Matrix4by3(
+	pub (i32, i32, i32),
+	pub (i32, i32, i32),
+	pub (i32, i32, i32),
+	pub (i32, i32, i32),
+);
+
+pub struct Matrix3by4(
+	pub (i32, i32, i32, i32),
+	pub (i32, i32, i32, i32),
+	pub (i32, i32, i32, i32),
+);
+
+pub fn transpose(m: Matrix4by3) -> Matrix3by4 {
+}
+```
+
+### Usage
+
+Here is a posible program to test your function
+
+```rust
+fn main() {
+	let matrix = Matrix4by3((1, 2, 3), (4, 5, 6), (7, 8, 9), (10, 11, 12));
+    println!("Original matrix {:?}", matrix);
+    println!("Transpose matrix {:?}", transpose(matrix));
+}
+```
+
+And it's output:
+
+```console
+student@ubuntu:~/[[ROOT]]/test$ cargo run
+Original matrix Matrix4by3((1, 2, 3), (4, 5, 6), (7, 8, 9), (10, 11, 12))
+Transpose matrix Matrix3by4((1, 4, 7, 10), (2, 5, 8, 11), (3, 6, 9, 12))
+student@ubuntu:~/[[ROOT]]/test$
+```
diff --git a/subjects/roman_numbers/README.md b/subjects/roman_numbers/README.md
index c4c8ea5c..2b6ff317 100644
--- a/subjects/roman_numbers/README.md
+++ b/subjects/roman_numbers/README.md
@@ -1,7 +1,7 @@
 ## roman_numbers
 
 ### Instructions
-Implement the From<u32> Trait to create a roman number from a u32 the roman number should be in subtractive notation (the common way to write roman number I, II, II, IV, V, VI, VII, VIII, IX, X ...)
+Implement the From<u32> Trait to create a roman number from a u32 the roman number should be in subtractive notation (the common way to write roman number I, II, III, IV, V, VI, VII, VIII, IX, X ...)
 
 For this start by defining the digits as `RomanDigit` with the values I, V, X, L, C, D, M and Nulla for 0