Tag: brain-exercises
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Brain exercising #1
I happened to see this problem on Twitter. It reminded me of my secondary school when I was passionate about solving math problems :)… I am thinking of a little corner of this blog for this sort of exercising. Claim: If $p$ is prime, all the coefficients in $(a+b)^p$ except the first and the last are divisible by $p$. If p is prime, all the coefficients in (a+b)^p except the first and last are divisible by p.
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Động não: Who ate the cake?
One day, a piece of cake meant for Eric went missing. His parents, Mr. and Mrs. Tan, suspected that one of his siblings ate the piece of cake and so questioned them. Here were their answers: Alfred said, “It wasn’t Charles. It was Darius.” Brenda said, “It wasn’t Darius. It was Alfred.” Charles said, “It wasn’t Brenda. It was Darius.” Darius said, “It wasn’t Alfred. It wasn’t Charles.” Exactly four of the eight statements were true.
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Động não: Alice, Betrice or Cynthia?
Một người đi kén vợ, và định chọn một trong ba cô gái Alice, Beatrice và Cynthia rồi cưới. Biết rằng mỗi cô gái đều luôn nói dối hoặc luôn nói thật. Một trong ba cô gái là phù thủy nhưng không biết rằng phù thủy luôn nói dối hay luôn nói thật. Dưới đây là những điều mà các cô gái nói với chàng trai. - Alice: Cynthia là phù thủy.