Using compound units: price/weight of sweets

Error

There was an error loading the page.

Contributors

Feedback

From users who are members of Transition to university :

Chris Graham	said	Ready to use	7 years, 8 months ago
Christian Lawson-Perfect	said	Needs to be tested	7 years, 8 months ago
Elliott Fletcher	said	Needs to be tested	7 years, 9 months ago

History

○

Christian Lawson-Perfect 2 years, 3 months ago

Saved a checkpoint:

Renamed 'name' to 'pname' to avoid a conflict with the marking algorithm.

Restore this checkpoint

○

Chris Graham 7 years, 8 months ago

Gave some feedback: Ready to use

○

Chris Graham commented 7 years, 8 months ago

Looks good. I've given the question a more descriptive title.

○

Christian Lawson-Perfect 7 years, 8 months ago

Gave some feedback: Needs to be tested

○

Christian Lawson-Perfect 7 years, 8 months ago

Saved a checkpoint:

I've changed the randomisation so that:

the weight is an unrounded number

the cost of the bag always ends in 9p.

The cost per 100g is between 50p and £2, which feels more reasonable.

I've reworded the advice, and added a part asking to compare to a pick'n'mix price so that there's a reason for converting to price per 100g.

Restore this checkpoint

○

Christian Lawson-Perfect 7 years, 8 months ago

Saved a checkpoint:

I've split the first two parts into separate questions.

Restore this checkpoint

○

Elliott Fletcher 7 years, 8 months ago

Published this.

○

Elliott Fletcher 7 years, 9 months ago

Gave some feedback: Needs to be tested

○

Elliott Fletcher 7 years, 9 months ago

Created this.

Name	Status	Author	Last Modified
Using compound units: price/weight of sweets	Ready to use	Elliott Fletcher	19/12/2022 12:21
Using compound units - speed	Ready to use	Christian Lawson-Perfect	20/11/2019 14:44
Using compound units - room hire price per hour and per minute	Ready to use	Christian Lawson-Perfect	20/12/2022 12:55
David's copy of Using compound units - room hire price per hour and per minute	draft	David Rickard	07/11/2018 21:05
David's copy of Using compound units: price/weight of sweets	draft	David Rickard	07/11/2018 21:05
David's copy of Using compound units - speed	draft	David Rickard	07/11/2018 21:05
David's copy of Using compound units - speed	draft	David Rickard	07/11/2018 21:06

There are 8 other versions that do you not have access to.

Question statement

{pname} goes to {pronouns['their']} local shop and buys a bag containing $\var{weight}$ g of sweets for £ $\var{cost}$ .

Give any introductory information the student needs.

			Name	Type	Generated Value

weight	integer	183
cost_per_g	number	0.0073536337
cost	number	1.29
min_kg_cost	number	7
max_kg_cost	number	7.05
person	dict	Dictionary with 3 entries
pname	string	Hannah
pronouns	dict	Dictionary with 5 entries
pick_n_mix_cost	number	0.56

Automatically regenerate variables?

Name

Data type

Value

xxxxxxxxxx
 
random(150..200)

JME function reference

Description

Weight of a bag of sweets, in grams

Describe what this variable represents, and list any assumptions made about its value.

Can an exam override the value of this variable?

Generated value: `integer`

183

This variable doesn't seem to be used anywhere.

Parts

Part a) Gap-fill
1. Gap Number entry
  Add
Part b) Gap-fill
1. Gap Number entry
  Add
Part c) Choose one from a list

Gap-fill

Ask the student a question, and give any hints about how they should answer this part.

How much do the sweets cost per $100$ grams?

£Unnamed gap per $100$g

Advice

a)

We are given the price of a bag of $\var{weight}$ grams of sweets.

To find the price per 100g of sweets we divide the price of a bag of sweets by its weight in grams and then multiply this by $100$.

\[\displaystyle\frac{\var{cost}}{\var{weight}} \times 100 = \var{(100*cost/weight)}.\]

\begin{align}
\displaystyle\frac{\var{cost}}{\var{weight}} \times 100 &= \var{(100*cost/weight)}\\ &= \var{dpformat(100*cost/weight,2)} \; (\text{rounded to $2$ decimal places}).
\end{align}

The sweets cost {pounds(100*cost/weight)} per 100g.

b)

To convert the cost from pounds per $100$ grams to pounds per kilogram we need to use the fact that $1\text{g} = \displaystyle\frac{1}{1000}\text{kg}$.

This means that $100\text{g} = \displaystyle\frac{1}{10}\text{kg}$.

We know from a) that sweets cost {pounds(100*cost/weight)} per 100g, which is the same as {pounds(100*cost/weight)} per $\frac{1}{10}$kg.

We want the price per one kilogram of sweets, so we multiply by $10$.

Note that we use the actual value of $\displaystyle\frac{\var{cost}}{\var{weight}} \times 100 = \var{100*cost/weight}$ here to ensure that our final answer is accurate.

\begin{align}
\var{100*cost/{weight}} \times 10 &= \var{dpformat(1000*{cost}/{weight},2)} \; (2 \; \text{d.p})
\end{align}

So, the sweets cost {pounds(1000*cost/weight)} per kg.

c)

We worked out in part a) that sweets cost {pounds(100*cost/weight)} per 100g when bought in the bag, so at {pounds(pick_n_mix_cost)} per 100g the Pick'n'Mix is {if(pick_n_mix_cost<100*cost/weight,'cheaper','more expensive')} than buying the bag.

Give a worked solution to the whole question.

Use this tab to check that this question works as expected.

There was an error which means the tests can't run:

Part	Test	Passed?
Gap-fill
Gap-fill		Hasn't run yet
Number entry
Number entry		Hasn't run yet
Gap-fill
Gap-fill		Hasn't run yet
Number entry
Number entry		Hasn't run yet
Choose one from a list
Choose one from a list		Hasn't run yet

This question is used in the following exams:

Units of measurement by Christian Lawson-Perfect in Transition to university.
Money by Christian Lawson-Perfect in Transition to university.
Weight and Mass by Christian Lawson-Perfect in Transition to university.
Questions using the random person extension by Christian Lawson-Perfect in Christian's workspace.
Nick's copy of Weight and Mass by Nick Walker in Nick's workspace.
Nick's copy of Units of measurement by Nick Walker in Nick's workspace.
Units of measurement [L1 Randomised] by Matthew James Sykes in CHY1205.
Lecture 1 by Matthew James Sykes in CHY1205.
David's copy of Units of measurement [L1 Randomised] by David Rickard in PHYS1010.
Module 3 by Niharika Singh in Niharika's workspace.
claire's copy of Weight and Mass by claire lines in claire's workspace.
claire's copy of Units of measurement by claire lines in claire's workspace.
All the good stuff by Chris Templet in Chris's workspace.
FoR Summative Maths Test by Angus Rosenburgh in Angus's workspace.
Core Maths Test 2025 by Angus Rosenburgh in Angus's workspace.

Loading...

Error

Using compound units: price/weight of sweets

Metadata

Taxonomy: mathcentre

Taxonomy: Kind of activity

Taxonomy: Context

Contributors

Feedback

History

Comment

Checkpoint description

Christian Lawson-Perfect 2 years, 3 months ago

Chris Graham 7 years, 8 months ago

Chris Graham commented 7 years, 8 months ago

Christian Lawson-Perfect 7 years, 8 months ago

Christian Lawson-Perfect 7 years, 8 months ago

Christian Lawson-Perfect 7 years, 8 months ago

Elliott Fletcher 7 years, 8 months ago

Elliott Fletcher 7 years, 9 months ago

Elliott Fletcher 7 years, 9 months ago

Error in variable testing condition

Error

Warning

Generated value: `integer`

Parts

Gap-fill

a)

b)

c)

Loading...

Error

Using compound units: price/weight of sweets

Metadata

Taxonomy: mathcentre

Taxonomy: Kind of activity

Taxonomy: Context

Contributors

Feedback

History

Comment

Checkpoint description

Christian Lawson-Perfect 2 years, 3 months ago

Chris Graham 7 years, 8 months ago

Chris Graham commented 7 years, 8 months ago

Christian Lawson-Perfect 7 years, 8 months ago

Christian Lawson-Perfect 7 years, 8 months ago

Christian Lawson-Perfect 7 years, 8 months ago

Elliott Fletcher 7 years, 8 months ago

Elliott Fletcher 7 years, 9 months ago

Elliott Fletcher 7 years, 9 months ago

Error in variable testing condition

Error

Warning

Generated value: integer

Parts

Gap-fill

a)

b)

c)

Generated value: `integer`