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It was only a matter of time before I'd stumbled upon a question from Singapore. If my source is correct, 11/12 years 12-year-old kids are supposed to answer this. Can you?
Previous iteration: #795879 (answer in #796077)
So proud to see my country’s Maths question represented here. It came out in the 2019 paper and received much attention - to the extent that our national daily covered it. Well done @Oxbitcoiner. You slayed it.
I think I am able to solve it, only because I have acquired an intuition for how such questions ought to be solved. Otherwise, I wouldn’t know how to tackle it.
The ability to spot patterns is important for our primary school Maths. Let me find similar questions from top schools’ prelim papers and post them here!
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In Portugal, 11-12 year-olds are in the 6th or 7th grade of compulsory education. Compulsory education starts at 6 years old, but pre-primary education is optional. In 6th and 7th grade, math classes cover first-degree equations, rational numbers, and trigonometry. I think these exercises are interesting, but wouldn't this kind of problem be used to differentiate the more intelligent students in the Singaporean education system? I'm just curious, because it seems a bit advanced for a regular difficulty level.
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a.
5
15
10
b. 250^2 = 62500
c. 49,4% ( (249*248)/2 = 30876)
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Can you elaborate on c? Don't think it is correct...
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I think I've found out:
pattern: For figure (f) even, there are more f gray triangles than white ones.
1234567
1166151528
03310102121
+2+4+6
Total triangle = 62500
62500/2 = 31250
gray = 31375 white = 31125
50,2%
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Great explanation
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Correct :)
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I seem to have missed the pattern of gray in the even figures, I've expanded the pattern and verified that it doesn't exist. Now I'm confused!
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didn't finish reading the question
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What do you mean? Is it the 11/12 years 12-year-old kids error?
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No, I had put a partial answer down and realized I hadn't read the full question. Since I don't have time to do more, I retracted my answer.
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Got it :)
I didn't see the partial answer.
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deleted by author
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