Assignment 3¶

For this assignment, you will need the information in:

• Expressions
• Names.

Don't forget to execute the cells in the notebook, that I've written for you.

Comments¶

In what follows, you will see me using comments. Comments start with a hash character - #. Python ignores everything after the hash character. This is useful to write text for you or others to read, inside your code.

Nothing happens - Python ignored everything after the hash character.

The problem¶

The problem is my bank.

I have a credit card debt of £500.

Let's give that debt amount, a name:

At the moment, the bank is nice enough to charge me 10% interest per year. Let's give that a name too.

The amount of interest, after one year, is therefore:

Then my total new debt will be:

I can also calculate my total new debt all in one go by multiplying by 1 + interest_rate - in my case - 1.1.

Now your turn¶

Add your code to the cell below, and execute it, to show my total debt after two years. Your code will probably start with:

my_debt * debt_increaser

Fill in the next cell, in the same way, to show my debt after three years.

Now show my debt after 10 years. You might want to use the power operator ** to do this.

An offer from the bank¶

The bank has just sent me a nice letter explaining that they are going to start charging me interest every week instead of every year. They value me as a customer, so, instead of dividing the annual interest rate by 52, they are going to divide it by 53 instead. But - is that a good offer?

Here is their proposed weekly interest rate:

That corresponds to:

So, starting from my original debt, I will owe this much after one week:

Fill in the cell below, to show how much I will owe after 52 weeks. You will probably want ** here again.

For extra cool points¶

Can you calculate roughly what the weekly interest rate has to be, in order to correspond to the 10% annual interest that I started with? There are several ways to do this, but you can try trial and error, if you like.