Tricky question from Letts.. how to explain to year 4 child
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Tricky question from Letts.. how to explain to year 4 child
A farmer has three goats, A, B, and C. Each goat is a different weight and is an exact number of kilograms. Goats A and B weigh a total of 20kg. Goats B and C weigh a total of 15kg. Goats A and C weigh a total of 17 kg.
What is the weight of each goat?
Is there a simple way to do this?
Any help gratefully received
Sleepy
What is the weight of each goat?
Is there a simple way to do this?
Any help gratefully received
Sleepy
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Re: Tricky question from Letts.. how to explain to year 4 ch
Because of the last two statements, Goat A weighs 2kg more than B.
So what two numbers make 20 that are '2 apart'? Answer 9 & 11.
Therefore A is 11kgs and B 9kgs. It then follows easily C weighs 6kg.
So what two numbers make 20 that are '2 apart'? Answer 9 & 11.
Therefore A is 11kgs and B 9kgs. It then follows easily C weighs 6kg.
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Re: Tricky question from Letts.. how to explain to year 4 ch
thank you secondtime, you make it look so easy.
Re: Tricky question from Letts.. how to explain to year 4 ch
Another simple way is to add 20kg + 15kg + 17kg = 52kg.
That will be double the total weight of all three goats as it is (A+B) + (B+C) + (A+C) - or 2 (A+B+C)
So the total of all 3 will be 26kg
We know A+B = 20kg - so C must be 6kg (i.e. 26kg-20kg)
We know B+C = 15kg - so A must be 11kg (i.e. 26kg-15kg)
We know A+C = 17kg - so B must be 9kg (i.e. 26kg-17kg)
That will be double the total weight of all three goats as it is (A+B) + (B+C) + (A+C) - or 2 (A+B+C)
So the total of all 3 will be 26kg
We know A+B = 20kg - so C must be 6kg (i.e. 26kg-20kg)
We know B+C = 15kg - so A must be 11kg (i.e. 26kg-15kg)
We know A+C = 17kg - so B must be 9kg (i.e. 26kg-17kg)
Re: Tricky question from Letts.. how to explain to year 4 ch
Great question. Which book is this from? Does it contain others which are as good as this?
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Re: Tricky question from Letts.. how to explain to year 4 ch
Hi Mystery
I have Pmed you the link to the book
I have Pmed you the link to the book
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Re: Tricky question from Letts.. how to explain to year 4 ch
Thank you Okanagan, that's a great method . Will explain both to DD
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Re: Tricky question from Letts.. how to explain to year 4 ch
Mystery,
There's another question in the same book (later on) so DD hasn't done this yet.. but here it is anyway
"Rosie bought three different hats. The red hat and the green hat cost a total of £16. The white hat and the green hat cost a total of £13. The white had and the red hat cost a total of £15. What is the cost of each hat?"
This appears on a level 4 paper too.
There's another question in the same book (later on) so DD hasn't done this yet.. but here it is anyway
"Rosie bought three different hats. The red hat and the green hat cost a total of £16. The white hat and the green hat cost a total of £13. The white had and the red hat cost a total of £15. What is the cost of each hat?"
This appears on a level 4 paper too.
Re: Tricky question from Letts.. how to explain to year 4 ch
SleepyHead wrote:Hi Mystery
I have Pmed you the link to the book
Hi SleepyHead,
I have Pmed you.
thanks
Re: Tricky question from Letts.. how to explain to year 4 ch
Hi SleepyHead,
Kindly PM me the link of the book.
Regards
Kindly PM me the link of the book.
Regards