The 1,600-Yen Science Shopping List
Emi and Kenta are at a convenience store near Ishioka Station with 1,600 yen from the class science fund. Their teacher's list says: 4 AA batteries at 240 yen each; 2 sheets of cardstock at 180 yen each; 1 roll of tape at 150 yen; 1 set of markers at 320 yen; and 1 pack of 5 plastic cups at 100 yen. At the register, Emi says, 'We have 1,600 yen. Batteries are 240 each and we need four. Cardstock is 180 a sheet and we need two. Tape is 150. Markers are 320. Cups are 100 for five.' Kenta says, 'The list says one tape. But last time our tape got wet, so should we buy two tapes just in case?' Emi replies, 'Ms. Ito said Group 3 has a full set of 12 markers we can borrow.' Kenta says, 'Then we don't need markers. But should we still buy the second tape?' The clerk is waiting.
1. Calculate the total of the five listed items. Which single item can be removed to bring the total under the 1,600-yen budget, and by how much?
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Add the listed quantities: 4 batteries × 240 = 960; 2 cardstock × 180 = 360; tape 150; markers 320; cups 100. The total is 960 + 360 + 150 + 320 + 100 = 1,890 yen. That is 290 yen over budget. Test single removals: removing tape (150) leaves 1,740; removing cardstock (180) leaves 1,710; removing cups (100) leaves 1,790; removing markers (320) leaves 1,570. Only removing the markers brings the total under 1,600, with 30 yen left. This also matches the dialogue: Ms. Ito says Group 3 has a full set of 12 markers the class can borrow.
2. Kenta suggests a second tape 'just in case.' What would that do to the budget, and what is the stronger reason to say no?
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After removing the markers, the total is 1,570 yen. A second tape adds 150 yen, making 1,720 yen, which is 120 yen over the 1,600-yen fund. The stronger reason to refuse is not only the price: the teacher's list specifies one tape, and the class fund is for listed materials. 'Just in case' is Kenta's worry, not a stated requirement. If Kenta is worried about wet tape, the group should ask Ms. Ito whether one tape is enough, not quietly change the list. The exam tests whether you can separate a real constraint from a reasonable-sounding extra.
3. Before paying, what should Emi confirm with Ms. Ito, and why is the confirmation necessary rather than assumed?
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Emi should confirm that Group 3's markers are actually available and that borrowing them is allowed for Emi's group. The dialogue says Ms. Ito mentioned the markers, but it does not say Group 3 agreed or that the set is complete. Emi should also confirm that the 1,600-yen budget covers the 1,570-yen total and that no other listed item is required. This matters because the whole plan depends on another group's property. Assuming the markers are available could leave Emi's group with no markers at all. The exam tests the difference between 'the teacher mentioned it' and 'it is confirmed.'