WitCH 122: Life on the Breadline

This is the second of our NAPLAN WitCHes. As with the first WitCH, this is from the 2018 Year 9 test, calculator part, and was also brought to our attention by Simon the Likeable. It’s probably more of a PoSWW, but what the hell. We’ll just label them all WitCHes, so as to keep the theme.

14 Replies to “WitCH 122: Life on the Breadline”

  1. “He sells the loaves for the same price and ….”

    Same price as what?

    Delete “sells the loaves for the same price and”
    It makes the question confusing. The table is all that is needed.

    Who writes and who proof reads this stuff? John Bennett, you’re needed here!

    (And as Tesla recently demonstrated, there’s no such thing as a profit on an order:

    https://www.news.com.au/finance/small-business/tesla-cancels-24k-pie-order-at-last-minute-leaving-bakery-owner-high-and-dry/news-story/7404060d11926c5b44afc0fd170197c0 )

      1. I agree with Terry, except that the total sales would be 212:50, making a nice profit of112:50. I suppose I am used to reading what people MEAN to say

  2. Either there is a daily maximum number of loaves he can make, or after a while… the cost per loaf becomes negative.

    I would have assumed a percentage decrease would be more realistic, rather than a flat rate for this reason.

    But then again… reality has no place in a NAPLAN test.

    1. That does seem to be the biggest problem – although, no one said the model would hold forever – just until the next extra 5 loaves sold.

      I also don’t like the confusion added by talking about the cost per loaf baked, even though they are sold in lots of 5, and how the total selling price is quoted instead of cost per loaf. Choose a lane!

    2. That does seem to be the biggest problem – although, no one said the model would hold forever – just until the next extra 5 loaves sold.

      I also don’t like the confusion added by talking about the cost per loaf baked, even though they are sold in lots of 5, and how the total selling price is quoted instead of cost per loaf. Choose a lane!

  3. The answer seems to depend on how he makes up the order of 25 loaves: 20+5, or 10+15, or even 5+5+5+5+5.

    Alternatively, one could infer from the table that, when he makes a batch of 25 loaves, the cost of making each loaf is $4.00, and the total selling price is $211.50. Then the profit is easy to calculate.

    1. “Infer” is an interesting and careful choice of terminology. Do you regard it as kosher to presume such inferring on such a test?

  4. This is nuts, absolutely nuts. Giving such a question without explaining the concepts of ‘fixed cost’, ‘ variable cost’ and ‘marginal cost’ is absolutely bonkers.

  5. I particularly dislike such questions as they impose a penalty on kids who understand the most and can think of the different mathematical possibilities and ambiguity. No mention of ‘linear relationship’ (which is what I guess they mean) or any other criterion.

    It’s a ‘Tell me what I’m thinking’ type of question as Terry has noted. Just wrong!

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