fixes in the exercises for the "Methods" chapter

Author: nakov

Content/Chapter-10-methods/exercises-methods/integer-to-base.md

@@ -10,7 +10,7 @@ Write a method **`IntegerToBase(number, toBase)`**, which takes as parameters an
 
 ## Hints and Guidelines
 
-In order to solve the problem we will declare a string, in which we will keep the result. After this we need to do the following calculations to convert the number.
+In order to solve the problem, we will declare a string, in which we will keep the result. After this we need to do the following calculations to convert the number.
 * Calculate **the remainder** of the number, divided by the base.
 * **Insert the remainder** in the beginning of the string.
 * **Divide** the number to the base.

Content/Chapter-10-methods/exercises-methods/notifications.md

@@ -1,9 +1,9 @@
 # Problem: Notifications
 
-Write a program, which takes an integer **`n`** and on the next lines prints **`n`** **messages** (for each message read a few lines). Each message starts with **`messageType`**: **`success`**, **`warning`** or **`error`**:
-- When **`messageType`** is **`success`** read **`operation`** + **`message`** (each on a new line).
-- When **`messageType`** is **`warning`** read only **`message`**.
-- When **`messageType`** is **`error`** read **`operation`** + **`message`** + **`errorCode`** (each on a new line).
+Write a program, which takes an integer **`n`** and **`n` input messages** and prints **`n` output messages**, based on the input. For each message read a few lines. Each message starts with **`messageType`**: “**`success`**”, “**`warning`**” or “**`error`**”:
+- When **`messageType`** is “**`success`**” read **`operation`** + **`message`** (each from a new line).
+- When **`messageType`** is “**`warning`**” read only **`message`** (from a new line).
+- When **`messageType`** is “**`error`**” read **`operation`** + **`message`** + **`errorCode`** (each from a new line).
 
 Print on the console **each read message**, formatted depending on its **`messageType`**. After the headline of the message print as much **`=`**, **as the length** of the said **headline** and print **an empty line** after each message (to understand in detail look at the examples). 
 

Content/Chapter-10-methods/exercises-methods/nth-digit.md

@@ -1,6 +1,6 @@
 # Problem: N-th Digit
 
-Create a method **`FindNthDigit(number, index)`**, which takes a number and index N as parameters and prints the N-th digit of the number (counting from right to left and starting from 1). After that print the result on the console.
+Create a method **`FindNthDigit(number, index)`**, which takes a number and index N as parameters and prints the N-th digit of the number (counting **from right to left** and starting from 1). After that print the result on the console.
 
 ## Sample Input and Output
 

Content/Chapter-10-methods/exercises-methods/string-repeater.md

@@ -10,11 +10,13 @@ Create a method **`RepeatString(str, count)`**, which takes parameters of type *
 
 ## Hints and Guidelines
 
-Add to the method below the input string to the result that you will print:
+In the method below, inside the loop, append the input string to the result, that you will finally return:
 
 ![](/assets/chapter-10-images/21.Repeated-string-01.png)
 
-Keep in mind that in C# concatenating strings in loops leads to bad productivity and is not recommended. Look for more effective solutions here: https://stackoverflow.com/questions/411752.
+Keep in mind that **in C# concatenating strings in loops leads to bad performance** and is not recommended. Learn more at: https://docs.microsoft.com/dotnet/api/system.text.stringbuilder#the-string-and-stringbuilder-types.
+
+Look for more effective solutions here: https://stackoverflow.com/questions/411752.
 
 ## Testing in the Judge System