The number 100

A lot can be said about this number. Let's take a look at some of its properties:

- 100 is the first 3 digit number when we count from 0 onwards.
- It consists of only 1's and 0's hence we can also find this presentation in binary numbers where it would represent the number 4.
- It is an even number.
- It's divisible by 1, 2, 4, 5, 10, 20, 25, 50, 100.
- It is equal to 10 squared.
- The square root of 100 is 10.
- It represents a century (in terms of years or cricket).
- There were 100 dalmatians, in the movie 101 Dalmatians, with spots, except for Spotty who only developed his spots at the end.
- It can be represented by the Roman numeral C.
- The year 100 was a leap year!
- If we factorize 100 we have: 100 = 2.2.5.5.
- It is a natural number (hence also rational and real).
- In terms of percentages it represents the full 'amount', i.e. 100% in a test would mean that you answered everything correctly. 100% profit would mean your profit will be equal to the cost price.

For some more interesting facts see: Facts about 100.

Pizza math

Not mathematically correct... But who cares? It's pizza!

Prime numbers

A prime number is a number which can only be divided by 1 and itself. This means that there is no other number which can divide into it such that the result is an integer.

Here are a few examples of prime numbers:
1, 2, 3, 5, 7, 11, 13, 17, 29, 31

The number 2 is the only even prime number, since all other even numbers are divisible by 2.

Very large prime numbers are used in encryption as 'keys' to secure data over networks.

MSc degree in Applied Mathematics

I am finally done with my MSc in Applied Mathematics! It's been almost two years of hard work and dedication and I am relieved that it is done.

Next year: PhD!

Blogging x 0 =Exam

With my final MSc exam a mere three days away, this blog would have to wait until ithe storm has passed before it will once again carry meaningful posts. Here follows the abstract of my presentation:

How fast will my coffee get cold?

With a not so difficult mathematical formula you can calculate exactly at what time will your cup of coffee (or tee) get cold (or to a certain temperature). It all depends on the room temperature, if it's colder the coffee will get colder faster and if it's a hot summer's day you coffee will stay warm for longer.

Let's take a look at the formula:







This is called a first-order differential equation. The T refers to the temperature at any given time t and A is the room temperature. The constant k indicates the rate at which the temperature will change.

Let's solve this equation:


Now we need to A (room temperature), B (which we can find by knowing the initial temperature of the coffee) and k (which is a bit more difficult to find).

Let's say A = 22˚C and that since water boils at 100˚C and we immediately make our coffee, let's assume that T(0) = 90˚C (Taking into account that it will cool off a bit when pouring and stirring).

Now we have the following:

To find the value of k we need to do some experimentation, where we determine the temperature of the coffee after some specific time. So let's say that after t=2 minutes we find that the temperature of the coffee is now 85˚C (I'm just guessing a value, for exact results one would have to take the actual temperature of the coffee after two minutes).

So now we find k:

Hence the equation becomes:

If I now want to know the temperature of my coffee after 20 minutes, let t = 20, then

and you will see that as time goes by the temperature will drop at a slower rate until it reaches the room temperature.

Happy coffee-drinking!