Answer:
<em>The program doesn't use comments; See explanation section for detailed line by line explanation</em>
<em>Program starts here</em>
def lettergrade(subject,score):
print(subject+": "+str(score))
if score >= 90 and score <= 100:
print("Letter Grade: A")
elif score >= 80 and score <= 89:
print("Letter Grade: B")
elif score >= 70 and score <= 79:
print("Letter Grade: C")
elif score >= 60 and score <= 69:
print("Letter Grade: D")
elif score >= 0 and score <= 59:
print("Letter Grade: F")
else:
print("Invalid Score")
maths = int(input("Maths Score: "))
english = int(input("English Score: "))
pe = int(input("PE Score: "))
science = int(input("Science Score: "))
arts = int(input("Arts Score: "))
lettergrade("Maths Class: ",maths)
lettergrade("English Class: ",english)
lettergrade("PE Class: ",pe)
lettergrade("Science Class: ",science)
lettergrade("Arts Class: ",arts)
Explanation:
The program makes the following assumptions:
Scores between 90–100 has letter grade A
Scores between 80–89 has letter grade B
Scores between 70–79 has letter grade C
Scores between 60–69 has letter grade D
Scores between 0–69 has letter grade E
<em>Line by Line explanation</em>
This line defines the lettergrade functions; with two parameters (One for subject or class and the other for the score)
def lettergrade(subject,score):
This line prints the the score obtained by the student in a class (e.g. Maths Class)
print(subject+": "+str(score))
The italicized determines the letter grade using if conditional statement
<em>This checks if score is between 90 and 100 (inclusive); if yes, letter grade A is printed</em>
<em> if score >= 90 and score <= 100:</em>
<em> print("Letter Grade: A")</em>
<em />
<em>This checks if score is between 80 and 89 (inclusive); if yes, letter grade B is printed</em>
<em> elif score >= 80 and score <= 89:</em>
<em> print("Letter Grade: B")</em>
<em />
<em>This checks if score is between 70 and 79 (inclusive); if yes, letter grade C is printed</em>
<em> elif score >= 70 and score <= 79:</em>
<em> print("Letter Grade: C")</em>
<em />
<em>This checks if score is between 60 and 69 (inclusive); if yes, letter grade D is printed</em>
<em> elif score >= 60 and score <= 69:</em>
<em> print("Letter Grade: D")</em>
<em />
<em>This checks if score is between 0 and 59 (inclusive); if yes, letter grade F is printed</em>
<em> elif score >= 0 and score <= 59:</em>
<em> print("Letter Grade: F")</em>
<em />
<em>If input score is less than 0 or greater than 100, "Invalid Score" is printed</em>
<em> else:</em>
<em> print("Invalid Score")</em>
This line prompts the user for score in Maths class
maths = int(input("Maths Score: "))
This line prompts the user for score in English class
english = int(input("English Score: "))
This line prompts the user for score in PE class
pe = int(input("PE Score: "))
This line prompts the user for score in Science class
science = int(input("Science Score: "))
This line prompts the user for score in Arts class
arts = int(input("Arts Score: "))
The next five statements is used to call the letter grade function for each class
lettergrade("Maths Class: ",maths)
lettergrade("English Class: ",english)
lettergrade("PE Class: ",pe)
lettergrade("Science Class: ",science)
lettergrade("Arts Class: ",arts)
. Plugging in the information gives you 
amperes of current.