Member of the e-learning unit in Newcastle University's School of Mathematics and Statistics.

Lead developer of Numbas.

I'm happy to answer any questions - email me.

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Christian Lawson-Perfect on Calculating Expected Values given a table of probabilities 8 years, 5 months ago

Saved a checkpoint:

This is a good question.

I've changed the titles of the films to randomly-generated ones because (a) they were a bit stereotypically boy-heavy and (b) they'll really date this question. There's also (c) are we allowed to use trademarks?

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Christian Lawson-Perfect on Using compound units: price/weight of sweets 8 years, 5 months ago

Gave some feedback: Needs to be tested

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Christian Lawson-Perfect on Using compound units: price/weight of sweets 8 years, 5 months ago

Saved a checkpoint:

I've changed the randomisation so that:

  • the weight is an unrounded number
  • the cost of the bag always ends in 9p.
  • The cost per 100g is between 50p and £2, which feels more reasonable. 

I've reworded the advice, and added a part asking to compare to a pick'n'mix price so that there's a reason for converting to price per 100g.

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Christian Lawson-Perfect on Using compound units: price/weight of sweets 8 years, 5 months ago

Saved a checkpoint:

I've split the first two parts into separate questions.

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Christian Lawson-Perfect on Using compound units - room hire price per hour and per minute 8 years, 5 months ago

Gave some feedback: Needs to be tested

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Christian Lawson-Perfect on Using compound units - room hire price per hour and per minute 8 years, 5 months ago

Saved a checkpoint:

Split off from a bigger question but entirely rewritten. The original question asked to calculate someone's pay per hour as pay per minute, which I can't imagine ever wanting to do.

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Christian Lawson-Perfect on Using compound units - speed 8 years, 5 months ago

Gave some feedback: Ready to use

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Christian Lawson-Perfect on Using compound units - speed 8 years, 5 months ago

Saved a checkpoint:

Split off from a larger question.

Heavily edited the advice to make sure no weird rounding errors happen, and fixed a fair bit of grammar.

The question now picks a physically reasonable speed and generates a time based on that.