# Wrong, But Useful: Episode 45

In this episode of Wrong, But Useful1:

• We're joined by @ajk_44, who is Alison Kiddle from NRICH in real life.
• We ask Alison: how long has NRICH been going? How do you tell which problems you've covered before?
• Colin's number of the podcast is 13,532,396,179 (he mistakenly calls it quadrillions rather than trillions, and sometimes transposes the 7 and 9 at the end. The fool.)
• Alison is NOT a trainspotter, but has just been to visit the new Cambridge North station and Shippea Hill, just to mess with statistics. See All The Stations for more! Rule 135
• Dave has no qualms about owning his geekiness: he likes collecting things, and asks about collecting the Sainsburys Lego cards. (Other supermarkets are available.) Colin erroneously refers to the Card Collector Problem rather than the Coupon Collector Problem. He wasn't having a good night.
• Dave sets out on the most elaborate segue ever attempted to ask Alison what kind of problems one might set a three-year-old.
• Practice needn't be boring; the idea of mathematical études
• via @colinthemathmo: park when it's wet; drive away when it's dry; the area of the wet patches left by your tyres, multiplied by the pressure in your tyres, gives an estimate for the weight of your car.
• Some tube map things: subways vs geography and @myboytrubetskoy's Roman Road tube map. Alison reminisces about the swerve in the road at RAF Scampton
• How big is a 72 point typeface?
• Easiness: a rant
• At least a silver star to @chrishazell72 for flipping pancakes. Dave hasn't done his homework, so we don't know if it's right.
• This month's puzzle: Agent Bond has been captured and is about to be killed by his enemy, Scaramanga. Scaramanga takes a six-chamber revolver and places two bullets next to one another, as shown above. He spins and locks the cylinder so a random chamber is on top, aims at Bond, and fires ... nothing happens. He then tells Bond that he will fire once more and if Bond is still standing afterwards he is free to go. Scaramanga gives Bond two options either he fires again right away or spins the cylinder of the revolver so a random chamber is on top and then fires. Which option makes it more likely that agent Bond will survive?" (via Brilliant, who I'm told can be a bit less than perfect with their data practices).

## Colin

Colin is a Weymouth maths tutor, author of several Maths For Dummies books and A-level maths guides. He started Flying Colours Maths in 2008. He lives with an espresso pot and nothing to prove.

### More from my site

1. Unfortunately, we have some technical problems with this episode, meaning the audio quality is worse than usual and Colin is less talkative than usual []

### 2 comments on “Wrong, But Useful: Episode 45”

That probability problem may have recently been on brilliant, but it was on Dave’s own “Reflective maths” blog years ago!!!

• ##### Colin

In that case, I hope he’ll know the answer!

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No spam ever, obviously.

##### Where do you teach?

I teach in my home in Abbotsbury Road, Weymouth.

It's a 15-minute walk from Weymouth station, and it's on bus routes 3, 8 and X53. On-road parking is available nearby.