Sunday, 27 March 2016

Quibans 25: 3 short food & drink stories

Three shorter Quibans, all related to food and drink.

From the Guardian:
Caffeine hit: what happens to Britain's 3bn empty coffee cups?
Britain’s coffee shops hand out 3bn paper cups every year. Yet, supposedly, fewer than one in 400 is being recycled.
“I see this as a house of cards,” says Peter Goodwin, one of the founders of Simply Cups, a company dedicated to the recycling of paper cups. By the middle of last year, his business recycled around 1m cups, and he hopes to raise that number to 6m by the end of the year. Even if he does, it will be a mere bean of our coffee consumption. “While everyone may have been under the impression that these products were being recycled, the reality is they more than likely weren’t,” he says.
The problems all begin with the cup. It is made from paper laminated with plastic, to be watertight. But the compound creates a complicated recycling proposition. It cannot be viably treated as pure paper.
  • How many cups per day? Per hour? (Bear in mind that coffee isn’t purchased as much in the middle of the night!).
  • The article says that fewer than one in 400 cups is recycled. How many is that?
  • What fraction of the cups are recycled by Simply Cups?

From the Daily Telegraph:
Budget 2016: Sugar tax on soft drinks
In a shock move, George Osborne announces new taxes on sugary drinks, with funds raised to go towards more sport in primary schools

The cash raised - an estimated £520 million a year - will be spent on doubling funding for sport in primary schools, the Chancellor said.
He suggested the changes were a chance to save a generation,
“We cannot have a long-term plan for the country unless we have a long-term plan for our children’s healthcare,” Mr Osborne told the Commons.
“Five-year-old children are consuming their body weight in sugar every year.

The two tiers of taxes mean that a few soft drinks such as Tango and Lilt will be exempt, because their sugar content is below 5g per 100ml.
A number of drinks, including Fanta and Sprite, with between 5g and 8g added sugar per 100ml, which will be taxed at 18 pence per litre.
But the highest tax of 24 pence per litre will fall on dozens of the most popular drinks, including Pepsi, Coca-Cola and Ribena.
Sugar content:

What questions can you ask/answer?  Here are some ideas:
  • How much tax will you pay on a can of drink?
  • If £520 million will be raised, how much is drunk per year?
    • (£520m divided by about 60m people gives about £9 in tax per person per year. If we assume that most drinks are taxed at 8p per can then £9 divided by 8p gives about 110 cans on average per person per year. That’s about one every three days.)
  • What percentage of its sugar does Irn Bru need to lose to get under 5g per 100ml?
  • What percentage of its sugar does 7Up need to lose to turn it into Sprite?
  • Taking Sprite as our starting point, how does Tango Orange compare? What about Coca-Cola? What about ginger beer?

From The Independent:
What would happen if everyone in the world became a vegetarian?
It is estimated that for every cow that is made into beef (remember there are about 1.5bn of them out there), it takes 15,000 litres of water to help them grow and for the land they graze.
Obvious questions:
  • How much water is that altogether?
  • What does 15,000 litres of water look like?
  • What does the total amount of water look like? Is that a lake-full, a sea-full, a drop in the ocean?

Friday, 25 March 2016

Quibans 24 - Tunnels

From the Cambridge News:
University of Cambridge study to tackle Cambridge transport – including tunnels and driverless cars

Some of the world's best transport engineers are turning their eyes to solving Cambridge congestion. Things like tunnels and innovative new vehicles are all on the table for the study commissioned by the University of Cambridge.
Professor Lord Mair is the university's head of civil and environmental engineering and one of the world's foremost experts on tunnels, having been involved with projects such as HS2 and Crossrail.
He told the News: "This is going to be a feasibility study which I think will really change the way Cambridge thinks about congestion and how people move around the city.
"Our remit is to look at options. It might be more or less direct, it could involve some underground, it could involve some overground. It could go within the city centre, and that would probably be underground.
"The important thing is, the ground conditions are very favourable for creating economic tunnels, particularly if they're relatively small in diameter." Lord Mair added that smaller tunnels of say 4 metres in width would cost about a quarter of those 8 metres in width, with the costs reducing as a greater proportion the narrower the tunnels got.

  • The obvious question is why a tunnel of half the width would cost about a quarter as much.
  • We could work out the cross-sectional area of a circular tunnel of width 8m and one of width 4m, and could also do the same for a square tunnel of widths 8m and then of 4m.  
  • Having established that the area is a quarter, why would this affect the cost?  (A quarter as much soil to dispose of, etc.)
  • Why might it not be a quarter of the cost?  
    • There are fixed costs that would be the same regardless of the width of the tunnel (eg survey costs, buying land, diverting streams, legal costs, etc).
    • The inside of the tunnel needs to be lined with concrete blocks.  How is this affected by halving the width?  Work out the perimeter of the circular tunnels (8m and 4m) and of the square tunnels.  
    • The calculation before is only approximate.  Look at the diagrams below and work out the area of the concrete if it is 30cm thick.
    • The smaller digging machine might not be a quarter of the cost.
    • You might not need a quarter of the people to run the machine.
    • The bigger machine might work more slowly so it takes longer.
    • Any others?  
  • Is a 4-metre tunnel big enough for 2-way traffic?  High enough for buses?  How small could the tunnels get?

Sunday, 6 March 2016

Quibans 23: Custard Creams

A short Quibans from the BBC website:
How have we coped without biscuits?
Britain has been experiencing a severe shortage of biscuits - an unforeseen and yet, for some, very serious impact of the recent Cumbria floods. How have we coped?
Storms Desmond and Eva left swathes of Cumbria, Lancashire and Yorkshire under water, causing widespread personal pain and huge economic cost.
They also submerged Carlisle's McVitie's factory ovens, halting production of custard creams, bourbons, ginger nuts and table water biscuits.
Used to consuming about 34,000 tonnes of biscuits a month, the British public were suddenly facing gaps on shop shelves.

However, there is now some hope for the British public - production of ginger nuts has restarted and should be back on the shelves by mid March.

There are some reasonably obvious questions:

  • How many packets of biscuits are consumed per person in Britain each month?
  • What about each year?
  • What weight of biscuits are consumed in total per year in Britain?
  • How much would they cost?


Friday, 4 March 2016

Quibans 22: Adele

From the BBC website:

What questions can you ask and answer?

This is brilliant because you can work out very easy things like:

  • How many copies were sold per second, per hour, per day, etc
My favourite question is:
  • When was the album released? (Which date?)
You can also do some 'unrounding' and decide that the "8 million" is not absolutely exact, so what will the upper and lower bounds for the release date be.

You can then do some estimating and decide roughly how much money Adele will have made during that month-and-a-bit.  


Quibans 85: Crime and Police figures

From the Cambridge News: Violent crime in Cambridge has nearly doubled in a decade as police numbers drop 9 APR 2018 Bottom of For...