04 January, 2014

## Math-Quiz.co.uk in numbers - a short summary of the year 2013

Beginning of the year, is the time when students receive summaries, ratings and reports based on the information collected from the previous year. And we are not an exception. We would like to demonstrate you how the year 2013 looked from our perspective as this year was rather significant for Math Quiz.
After a fairly quiet start in the year 2013, it was time for changes. An important goal of the Math-Quiz development that we have for set ourselves in 2013 was to change the layout of our website. The old layout still remembered the year 2010 and the times when the site started to operate. This change was a priority for us.

Finally, on July 22nd we have published the graphical changes . Lots of experiments with the arrangement of elements on the page. We took into account all your suggestions, because in all this redesign confusion, the user is the most important .

16 October, 2013

## Clock, angles and arcs

Recently we received an interesting GCSE maths question on our facebook profile. We decided to share the problem with you, as perhaps it will help someone in revising with GCSE material. The problem is as follows:

The hour hand on a clock is 12cm long. What area does it pass over in 5hrs. Take 3.142 as $\pi$

Solution to this problem is:

You are looking for area of an arc. Formula for an arc area is: $A=\pi \cdot {r}^{2}\cdot \left(\frac{C}{360°}\right)$

Where r is radius, $r=12cm$

C is central angle in degrees.

If a clock passes 5hours, it means it covers 5 hours out of 12 (full circle), it means: $C=\frac{5}{12}\cdot 360°=150°$

Now using arc area formula: $A=3.142\cdot {12}^{2}\cdot \left(\frac{150}{360}\right)=3.142\cdot 144\cdot \left(\frac{5}{12}\right)=188.52c{m}^{2}$

We have seen similar questions where the clock passed certain amount of minutes or even seconds and the working is exactly the same. All you have to do is work out the angle and put it into the formula. On top of that, in order to help you with revision with geometry material, the following tests may be useful as well:

Angles, Straight Lines

Areas and Volume

Circles

01 September, 2013

## First contest !

Tomorrow begins a new school year. We have a riddle for you to remindyou to properly set awatch . First three persons to give the correct answer are going to be awarded with a Premium account . And learning Maths will be easier. Here's a question:

I tried to fix aclock. Now, an hour hand works great, but the minute hand moves in the opposite direction at a constant speed, passing an hour hand every 80 minutes.

Question: If at 6:30 my clock shows the correct time, when will it show the correct time again?