Runners in a race

11 Plus Maths – Preparation and Information

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MCLC
Posts: 335
Joined: Sat Jan 09, 2016 6:45 pm

Runners in a race

Post by MCLC »

Hello all,

Just trying to compose a list of answers for DD. Would someone mind helping with the following?

Two runners are having a race. Gary starts running from the start line at 10m/s. Two seconds later Andy starts running from the start line at 12m/s.

How long after Gary starts running does Andy catch up with him?

How far are they both from the start line when Andy catches up with Gary?

Thank you!
Guest55
Posts: 16254
Joined: Mon Feb 12, 2007 2:21 pm

Re: Runners in a race

Post by Guest55 »

MCLC wrote:Two runners are having a race. Gary starts running from the start line at 10m/s. Two seconds later Andy starts running from the start line at 12m/s.

How long after Gary starts running does Andy catch up with him?

How far are they both from the start line when Andy catches up with Gary?
Gary has gone 20 m when Andy starts running - Andy is running 2 m/s faster so he takes 10 seconds to catch up - after 10 seconds he has gone 12 x 10 = 120 metres.

Or you could look at each second
GARY 0, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140,
ANDY 0, 0, 0, 12, 24, 36, 48, 60, 72, 84, 96, 108, 120,

If you line these up you can see the answer
MCLC
Posts: 335
Joined: Sat Jan 09, 2016 6:45 pm

Re: Runners in a race

Post by MCLC »

Thank you!

Sorry, how do I go about working out the second part of the question?
Guest55
Posts: 16254
Joined: Mon Feb 12, 2007 2:21 pm

Re: Runners in a race

Post by Guest55 »

You should have both answers? 12 seconds and 120m.
MCLC
Posts: 335
Joined: Sat Jan 09, 2016 6:45 pm

Re: Runners in a race

Post by MCLC »

Ah I see, thanks. Is it better to draw out the options like you did in a question such as this?
Guest55
Posts: 16254
Joined: Mon Feb 12, 2007 2:21 pm

Re: Runners in a race

Post by Guest55 »

I think I'd have tackled it the first way but a child can do it logicall the second way with no algebra or use of formulae.
Surferfish
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Joined: Fri Mar 10, 2017 5:06 pm

Re: Runners in a race

Post by Surferfish »

If Andy can run 120m in 10 seconds I'd suggest that he be tested for performance enhancing drugs! :shock:
Guest55
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Joined: Mon Feb 12, 2007 2:21 pm

Re: Runners in a race

Post by Guest55 »

Surferfish wrote:If Andy can run 120m in 10 seconds I'd suggest that he be tested for performance enhancing drugs! :shock:
Just shows someone setting questions to work out easily without thinking if the answer is sensible - one of my pet hates. A bit like the one about a jug which contained 240 litres. :roll:
anotherdad
Posts: 1763
Joined: Mon Jan 24, 2011 5:33 pm

Re: Runners in a race

Post by anotherdad »

Guest55 wrote:
Surferfish wrote:If Andy can run 120m in 10 seconds I'd suggest that he be tested for performance enhancing drugs! :shock:
Just shows someone setting questions to work out easily without thinking if the answer is sensible - one of my pet hates. A bit like the one about a jug which contained 240 litres. :roll:
I saw many odd things in my previous career. When Key Skills were introduced for apprentices, there was a call for maths problems to be contextualised. Nothing wrong with that of course, it's a very sensible thing to embed the maths apprentices need to demonstrate in problems they are likely to encounter in their discipline. Sadly, it quickly became apparent that there was a lazy way of doing things...

Original problem: A boat leaves shore at an angle of x degrees and travels x metres to a lighthouse, etc, etc.

"Contextualised" problem: A plumber is on a boat that leaves shore at an angle of x degrees..... :lol:
yoyo123
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Location: East Kent

Re: Runners in a race

Post by yoyo123 »

Diagrams and trial and improvement are perfect for KS2, it helps them work their way around a problem and think mathematically, which makes it so much easier for them to formalise this in secondary school.
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