The delivery plan is missing, the van is almost here, and 120 supply kits are waiting to be packed. In this math mystery for students, you’ll use the clues to rule out a plan that cannot work. Then you’ll decide which of the remaining plans is best.
There may be more than one answer you can defend. The strongest answer will use accurate math and explain whyyour choice makes sense.
The Case
Students assembled 120 supply kits for a community event. Every kit must go in a box, and every box must be filled to its listed capacity.
The delivery van can carry no more than 12 boxes in one trip. The driver will arrive in 25 minutes, and volunteers need 2 minutes to load each box. The school can spend no more than $40 on boxes.
Three box types are available:
| Box type | Kits per box | Cost per box |
|---|---|---|
| A | 12 | $4.00 |
| B | 10 | $3.00 |
| C | 8 | $2.50 |
A note beside the supply cart reads:
“Choose one box type. Pack all 120 kits. Make one trip.”
The person who wrote the original delivery plan is gone for the day. Now the volunteers are looking to you for a decision.
Investigate the Clues
Check each box type before choosing. You may calculate on paper, but write your answer and reasoning in the comments.
For each type, find:
- The number of boxes needed to hold 120 kits
- The total cost of those boxes
- The time needed to load them
- Whether they fit in the van for one trip
A plan works only if it meets all four rules: it carries every kit, uses no more than 12 boxes, takes no more than 25 minutes to load, and costs no more than $40.
Solve the Mystery: Which Plan Is Best?
First, rule out any box type that breaks a rule. Then choose the best plan from the options that remain.
What matters more for this delivery: spending less money or finishing the loading sooner? Neither priority is automatically wrong. Your answer depends on which one you choose and how well you defend it.
Think about this question before you post:
If a classmate chose a different box type, what might they value more than you do?
Post Your Answer
Write one comment that explains your decision. Include your box choice, your calculations, the reason you rejected any plan that cannot work, and the priority that guided your final choice.
You can use this frame:
I would choose Box ___ because ___. We need ___ boxes to hold 120 kits because ___. The boxes would cost ___ and take ___ minutes to load. Box ___ cannot work because ___. Someone might choose Box ___ instead if they care more about ___.
Show how you got your numbers. A box letter alone does not explain your thinking.
Reply to at Least Three Classmates
After posting, read your classmates’ ideas and reply to at least three different people. In each reply, refer to a specific calculation or reason they gave. Add a question, compare their choice with yours, or explain how their thinking changed your mind.
These sentence frames can help:
- “I agree with your choice of Box ___ because your calculation shows ___. I also noticed ___.”
- “I chose a different box because I prioritized ___. Why did you decide that ___ mattered most?”
- “Your plan meets the ___ rule because ___. Did you also check the ___ rule?”
- “We calculated different costs. I got ___ × ___ = ___. Can you show me how you got yours?”
- “Your explanation made me reconsider ___. I still choose ___ because ___.”
It is okay to disagree. Be respectful, check the math, and explain your idea clearly.
Before You Submit
Read your comment one last time. Can someone follow your calculations? Does your plan meet every rule? Have you explained why your choice is best from your perspective?
Once you have posted your answer, return to the discussion and reply thoughtfully to at least three classmates. The mystery becomes more interesting when you see how someone else can use the same clues to make a different, well-supported decision.
34 Responses
I would choose Box,B because the school cant spend more than 40 dollars We need 12 boxes to hold 120 kits because 10 kits in each box would only add up to 39 dollars. The boxes would cost 3 dollars and take 24 minutes to load. Box,A cannot work because the cost would go over 40 dollars. Someone might choose Box A instead if they care more about box B.
12 divided by 120 is 10, and if it cost 4 dollars for one box, it would be 40 dollars instead of 39.
I would choose Box A because it only takes one trip to complete the order. We need 10 boxes to hold 120 kits because Box A holds 12 kits per box, meaning we need 10 boxes. The boxes would cost 40$ and take 20 minutes to load. Box C cannot work because we would need 15 boxes. Someone might choose Box B instead if they care more about money because it only cost 36 dollars.
I agree with your choice of Box A because your calculation shows how it added up to 120.
I agree with box A because it perfectly matches the 10 box requirement for the trip. It keeps the total loading time to just 20 minutes and fits exactly within the school’s $40.00 budget.
I agree with this because I also said Box A is the best option, none of the other boxes fit as good as Box A.
I agree with this statement because box A is exactly the amount the school pays.
I would choose Box,B because the school cant spend more than 40 dollars We need 12 boxes to hold 120 kits because 10 kits in each box would only add up to 39 dollars. The boxes would cost 3 dollars and take 24 minutes to load. Box,A cannot work because the cost would go over 40 dollars. Someone might choose Box A instead if they care more about box B.
I agree with your choice of Box A because your calculation shows how it added up to 120.And the requirement.
I would choose Box A because it matches the school budget. We need 10 boxes to hold 120 kits because it holds 12 kits per box, and we have 10 boxes.The boxes would cost 40$ and take 20 minutes to load. Box C cannot work because it will take more time to load . Someone might choose Box B instead if they care more about the price.
I agree with this statement because I also said something similar to this.
I agree with your choice of Box A because your calculation shows how it added up to 120.
I would choose Box A because it has the 10 boxes requirement it will take me like 25 mins tho to pack all the boxes and its might fit right it will be $40 and that how you do it
I would choose box A because it has the most kits per box. We need 10 boxes to hold 120 kits because I multiplied 10 by 12 and got 120. The boxes would cost $30 and take 45 minutes to load. Box c cannot work because if there were twelve boxes, there would only be 96 kits. Someone might choose box c if they care more about money.
I would choose Box B because Its not that cheap and the school can’t spend more than 40 dollars. We need 12 boxes to hold 120 kits because 10 kits in each box would leave us with 1 dollar left. The boxes would cost 3 dollars and take 20 minutes to load. Box A cannot work because its 4 dollars ber kit and probably go over the 40 dollars. Someone might choose Box C instead if they care more about cost.
I would choose box B because its easier. We need 12 boxes for 120 kits because 10 x 12= 120. The boxes would cost 36 dollars . It would take 24 minutes.
I would choose box b because it costs 36$ which leaves 4$ left over. It would take around 24 minutes to load which isn’t over the deadline. Its also perfect because the van can only carry 12 boxes and it saves money because it takes about 20 mins to load. Its also smarter because its a stronger option than A, it might take more time.
I would choose box A because it would take less box’s. We need 10 boxes to hold 120 kits because it would be 12 * 10= 120. the boxes would cost $40.00 and take 24 minutes to load. box C wouldn’t work because it would take more boxes and it would take longer to load the kits.Someone might choose box B instead if they care more about how much it would cost or how long it would take to arrvive.
I would choose box type A because 12 times 10 is 120 I also noticed that if you do $4.00 times 10 its 40 dollars which is the amount of money the school can use so this makes it easy for them to purchase it .
I would perfect mathematical observation.Multiplying by 10 is a fantastic shortcut because you just move the decimal point one place to the right (or add a zero to the whole number). Since $4.00 × 10 = $40.00, it keeps the budget very clean and straightforward for the school to track.To help you finish up with this budget or math problem, I can help you figure out:If $40.00 covers the total cost including any taxes or shipping How many items they can buy if the budget changes to a different amount (like $100 or $200)The total cost if they need to buy a different quantity, like 15 or 25 items
I would choose Box,B because the school can’t spend more than 40 dollars, We need 12 boxes to hold 120 kits because 10 kits in each box would add up to 39 dollars.The boxes would cost 3 dollars, and take 24 minutes to load. Box,A cannot work because the cost would go over 40 dollars. Somebody might choose Box,A instead of box B.
I would choose Box B because it stays under budget and is under the time limit. We need 12 boxes to hold 120 kits because Box B can equally fit 120 with 10 in each box. The boxes would cost $36 and take 24 minutes to load. Box C cannot work because it takes 15 boxes, which is too much. Someone might choose Box C instead if they care more about the time.
I would choose Box because we need boxes to hold 120 kits because. The boxes would cost and take minutes to load. Box cannot work because Someone might choose Box instead if they care more about.
I would choose Box A because 12 times 10 is 120 . We need 10 boxes to hold 120 kits because 10 times 12 is 120. The boxes would cost $40 and take 24 minutes to load. Box C cannot work because It just wont work and A is a better option. Someone might choose Box B instead if they care more about if they care more about how much it would cost or how long it would take to arrvive.
I would go with Box B since the school is only allowed to spend forty bucks. Since 10 kits in each box would only total $39, we need 12 boxes to house 120 kits. The crates would take a whole day to load and cost three bucks. Because the cost would exceed forty dollars, Box, A cannot function. If someone is more concerned about Box B, they might select Box A.
I would choose Box B because 10 times 12 is 120. We need 10 boxes to hold 120 kits because there are 12 kits for each box. The boxes would cost $36 and take 24 minutes to load. Box C cannot work because it wouldn’t have the exact amount of boxes. Someone might choose Box A instead if they care more about how much it costs, since it’s 40 dollars and takes less time to load.
I would choose Box B because 1 We need 10 boxes to hold 120 kits because 18. The boxes would cost 17 and take 1 minutes to load. Box A cannot work because it cant. Someone might choose Box A instead if they care more about me.
I don ´ t agree because boxes should not cost a lot of money. because a lot of people would just throw them away.so we should not cost not even a dime they should be free. and should not cost money. so I don´t agree at all.
I would choose box A because we need around 12 boxes to hold 120 kits because 10 x 12 would be 120. The boxes would cost $4.00. Multiply 4 x 10 would be 40 dollars. It would take around 24 minutes to load. Boxes C would take too much time to load and I think Boxes B will be more money to spend.
I would choose Box A because 12 x 10 is 120 Which means we need 10 boxes to hold 120 kits.The boxes would cost $40 because if we need 10 boxes at each box cost $4.00 so you just have to do 4 x 10.
I would choose Box A because we would use less boxes. We need 10 boxes to hold 120 kits, because 12 x 10 equals 120. The boxes would cost $40.00 and take 24 minutes to load. Box C cannot work because the boxes needed is 10 and for C the boxes are 8. Someone might choose Box B instead if they care more about finishing.
I agree with your choice of Box because your calculation shows that is kinda right and I also noticed that you really fouced on it
I would choose Box B because its the right amount of money. We need 12 boxes to hold 120 kits because 10 x 12 = 120. The boxes would cost $36.00 and take 24 minutes to load. Box C cannot work because its less boxes. Someone might choose Box A instead if they care more about doing it faster.
would choose Box A because it is the fastest option. We need 10 boxes to hold 120 kits because \(120 \div 12 = 10\). The boxes would cost $40.00 and take 20 minutes to load. Box C cannot work because it requires 15 boxes and takes 30 minutes, which breaks the van and time limits. Someone might choose Box B instead if they care more about saving money ($36 vs $40).