Plus Blog

July 31, 2012

Do more people in a boat help or do they slow it down? Image: Yanid.

We're getting very excited about the medals that will be awarded in canoeing and kayaking over the next three days. But here's a question: does having lots of paddlers helps or slow the boat down? The kayak with two paddlers has twice as many "engines" to power it, but it also has twice as much weight to drag through the water. Which is the dominant factor? It's something we should be able to work out using some relatively straight-forward maths. And indeed we can — you can find the answer here.

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July 30, 2012
Lizzie Armitstead

Lizzie Armitstead has won the silver medal in the women's road race. Image: johnthescone.

The first Olympic weekend is over! GB has excelled at cycling and swimming, snatching a silver and a bronze, and there have been other good performances too. Of course it's the taking part, not the winning, that counts, but let's face it: it's the medals, especially the gold ones, we all get most excited about. So while we were sitting glued to the telly watching the joys of weightlifting, archery and judo we started pondering some serious questions. Are all gold medals equal in value? How do poor countries perform compared to rich ones? How do the weather conditions of the day, for example the wind, influence an athlete's performance? What about the effect of altitude? And that of chance? Thankfully we remembered that two good friends of Plus have written an article looking at just these questions — so if you'd like to know some answers, read The maths of gold medals: Four Olympic thoughts.

Our sister site Maths in sport: Countdown to the Games also has some interesting content relating to some of the disciplines in which medals have already been awarded. There's an activity aimed at A-level students, exploring the effect of altitude on a weightlifter's performance, seeing that the weight of objects decreases as you move further away from the centre of the Earth. And, noting that some weightlifters are very big people indeed, we recommend the video of a lecture called David and goliath: Strength and power in sport, given by John D. Barrow, on the role of an athlete's size on his or her performance. But if weightlifting isn't your thing, you might prefer this key stage 3 activity, which comes with a nice little interactive applet, to see how an archer should adjust the sight to adapt to new situations. Who said that there was no maths in sport?

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July 26, 2012

Yesterday we brought you two Olympic brainteasers. Here are another two. Enjoy!


Fencing Tournament

Alice, Becky, Charlotte, Daphne, Elsie and Fran decide to compete in a fencing tournament. Each competitor has to fence against every other competitor. A match results in either a win or a loss.

  • No competitor lost all their matches, but one person won all their matches.
  • Daphne won her match against Becky.
  • Alice and Elsie won the same, odd, number of matches, but Alice lost to Elsie.
  • Becky and Fran won a total of seven matches
  • Charlotte won only one match, against the only other person who also won only one match.

Can you deduce what all of the results were?


In a hockey competition, four teams were to play each other once. 2 points were awarded for a win, and 1 point for a draw.

After some of the matches were played, most of the information in the results table was accidentally deleted.

Team Played Won Drawn Lost For Against Points
A 4 4
B 5 5
C 0 4 2
D 0 3 0

Can you work out the score in each match played?

These brain teasers come from our sister site NRICH, which also has detailed teachers notes for them.

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July 25, 2012

While the athletes are flexing their muscles, why not train your brain with these two Olympic puzzles? There'll be another two tomorrow.

Medals Count

Given the following clues, can you work out the number of gold, silver and bronze medals that France, Italy and Japan got?

  • Japan has 1 more gold medal, but 3 fewer silver medals, than Italy.
  • France has the most bronze medals (18), but fewest gold medals (7).
  • Each country has at least 6 medals of each type.
  • Italy has 27 medals in total.
  • Italy has 2 more bronze medals than gold medals.
  • The three countries have 38 bronze medals in total.
  • France has twice as many silver medals as Italy has gold medals.

Football Champ

Three teams A, B and C have each played two matches.

Three points are given for a win and one point to each team for a draw.

The table below gives the total number of points and goals scored for and against each team.

Fill in the table and find the scores in each match.

Teams Games Played Won Drawn Lost Goals For Goals Against Points
A 2 5 3 3
B 2 2 1
C 2 3 2 4

These brain teasers come from our sister site NRICH, which also has detailed teachers notes for them.

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July 24, 2012
Usain Bolt

Can you out run Bolt? Image: Jmex60.

What can you do to out sprint Usain Bolt to the taxi rank? Was he unlucky to lose at the Jamaican trials or is Yohan Blake really faster? Get in training for a summer of sport with a talk from John D. Barrow at the Science Museum tomorrow, 25th July. The talk is part of an evening dedicated to science and sport, part of the Science Museum Lates series. You'll also be able to test out the devices helping to keep athletes' bones in top condition, from hand-held scanners to vibrating platforms, and be part of the Science Museum sports day with a variety of thrilling events. The evening starts at 6:45pm and finishes at 10:00pm and all events are free. See the Science Museum website for more information.

John D. Barrow is the director of the Millennium Mathematics Project, of which Plus is a part, and he regularly writes for Plus, often on maths and sport. You can see all his articles here. Also, don't forget our sister site Maths and sport: Countdown to the Games and our teacher package on maths and sport.

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July 24, 2012

Are you ready for the Games? Andy Murray passes the Olympic Flame to Venus Williams at Wimbledon on the 66th day of the torch relay.

Will Britain be able to turn the home advantage into the top spot on the medal table this Games? Predicting medal counts is a tricky business, but, never afraid of a challenge, we will reveal our own predictions for the top 20 countries here on Plus on Friday. In the meantime, why not come up with your own mathematical method for predicting the results? To help you along, here are two articles we produced for the 2008 Games in Beijing:

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