Question on Ratio

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MalikN

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Jul 18, 2020
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I wonder if anyone could provide me with some insight into the following problem.

The question is below but i cannot for the life of me find why Kenny is wrong. I have also provided a bar model of my working, thank you.

1595055006123.png
 
MalikN said:
I wonder if anyone could provide me with some insight into the following problem.

The question is below but i cannot for the life of me find why Kenny is wrong. I have also provided a bar model of my working, thank you.

View attachment 20509
Click to expand...
Your work looks correct to me - given the "problem statement".

Is this the complete problem - or there were other parts before this?
 
The way you have shown it, the "18 sweets" is 1/3 of what Jenny has now, not 2/3 of what she originally had. If 18 was 2/3 of what she had then 18/2= 9 is 1/3 so originally she had 3(9)= 27 sweets.
 
HallsofIvy said:
The way you have shown it, the "18 sweets" is 1/3 of what Jenny has now, not 2/3 of what she originally had. If 18 was 2/3 of what she had then 18/2= 9 is 1/3 so originally she had 3(9)= 27 sweets.
Click to expand...
I would have interpreted the picture differently.

As the written problem statement states - Jenny gives 1/3 of what Jenny had originally to Kenny and Kenny has 18 sweets now. Kenny started with 0 - so Jenny must have started with 54.
 
It is very easy to read the "1" in "1/3" in the problem as a "2"; I did that myself. (I just had my eyes tested, and I do need a new lens for my left eye!)

Kenny is not wrong. The problem is wrong. I would not be surprised if the author intended that to be 2/3; or perhaps that the question was about how many Jenny has now.

As for the picture, I would at least show one 18 crossed off to show it was removed; and I might put that and Kenny's in a different color, to make it clear what was then and what is now. Really, I'd make two pictures.
 
Thank you, i must apologise. The model has skipped a few steps and doesn't reflect the change of 18 sweets from Jenny to Kenny.

The problem was defined in a obscure scheme of work i found on my schools network; it was titled "common misconceptions" leading me think i was wrong.
 
The problem clearly claims that Kenny is wrong; I think the authors fooled themselves, and gave Kenny the right answer by mistake.

I found this problem in a few other places that got it from the same source. Other problems ask the student to decide whether Kenny or Jenny was right. None of the sources I found give a "correct" answer to confirm what they intend for you to say.

So you're right; don't worry about it. (Unless you want to tell someone they have a bad problem on their site.)
 
My apologies. My vision is not what was and I misread the "1/3" in the original post as "2/3".
 
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