Question 9
MediumOriginal questionFive students, Farhan, Gurpreet, Nandini, Joseph and Lalremsiami, each take a different elective (Physics, History, Economics, Biology or Geography) and each keep their notes in a notebook of a different colour (red, blue, green, yellow or white). The following is known:
1. The student who takes History uses the blue notebook.
2. Gurpreet's notebook is red.
3. The Physics student's notebook is white.
4. Farhan takes neither History nor Geography, and his notebook is neither yellow nor white.
5. Joseph's notebook is neither blue nor white, and he does not take Biology.
6. Nandini does not take History.
7. The Biology student and the Geography student are Gurpreet and Joseph, in some order.
Among the five students, who keeps notes in the green notebook?
Show the answer and explanation
Correct answer: D
Explanation
Clue 7 says Biology and Geography go to Gurpreet and Joseph; Joseph does not take Biology (clue 5), so Joseph takes Geography and Gurpreet takes Biology.
Farhan does not take History (clue 4), and not Physics either, because the Physics notebook is white (clue 3) and Farhan's is not white. So Farhan takes Economics.
Physics and History are left for Nandini and Lalremsiami. Nandini does not take History (clue 6), so Nandini takes Physics (white notebook) and Lalremsiami takes History (blue notebook, clue 1).
Gurpreet has red (clue 2). Green and yellow are left for Farhan and Joseph; Farhan's is not yellow, so Farhan has green and Joseph has yellow.
The green notebook belongs to Farhan.
Worth noting
Joseph is the tempting answer if clue 4's colour condition is overlooked.
- Concept
- Completing a grid by elimination in the last two cells
- Typical timeTypical
- 80 s
- Your timeYours
- —
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