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### History and Feedback

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#### Christian Lawson-Perfect2 years, 6 months ago

Gave some feedback: Ready to use

#### Christian Lawson-Perfect2 years, 6 months ago

Saved a checkpoint:

Changed the storm to an electrical fault, so it's more plausibly instantaneous.

Improved some of the wording in the advice.

#### Chris Graham2 years, 6 months ago

I've changed the wording to be, I think, clearer. I've not marked it ready to use, as I would be grateful for a second opinion.

Published this.

#### Lauren Richards2 years, 7 months ago

I have made the changes you suggested and made sure the LCM will not be either of the given numbers.

#### Lauren Richards2 years, 7 months ago

Gave some feedback: Needs to be tested

#### Christian Lawson-Perfect2 years, 7 months ago

Gave some feedback: Has some problems

#### Christian Lawson-Perfect2 years, 7 months ago

Saved a checkpoint:

Part a is a bit too simple for an incoming university student.

This question should focus just on calculating least common multiples. Remove part a, leaving the nice wordy question. You could have another very simple separate question asking to find the LCM of two numbers when:

• they're coprime;
• their GCD is bigger than 1 but not equal to either number;
• one is a multiple of the other.

I think it should be "platform A" instead of "track A".

I got periods of 12 and 6 minutes for the two platforms - could you make sure that the LCM isn't either of the given numbers?

#### Bradley Bush2 years, 7 months ago

Good concise question, just a few notes:

• Could the statement be a more formal definition of a multiple followed by what you've already written as a way of thinking of it?
• The first part was really straight forward although it made me feel guilty for not instantly remembering my $16$ times tables.
• For the second part, I think that you need to either make it clear that a train needs to be present on exactly the same minute to clash or maybe think of a different example so that using multiples makes more sense. I.E. if the trains were stopping 1 minute apart, surely they would clash too?
• Maybe you could phrase the question in an alternate reailty where there has yet to be a storm and both tracks are working then just ask for the time when there is a train on both tracks? I'm struggling to be very imaginative here.
• In the advice, it might be good to hint to the fact you are caling lowest common multiples LCM before you start using it by in the first instance of saying lowest common multiples just putting lowest common multiples (LCM) for reference?

Other than that, great question, I learned some times tables :)

#### Lauren Richards2 years, 7 months ago

Gave some feedback: Needs to be tested

#### Lauren Richards2 years, 7 months ago

Created this.

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