My engineering brain says it's 3.25.
4% is ~ 5%. 10% of 75 is 7.5. To get the 5% I have to divide it by 2, so 4% of 75 is close to 3.25. I will have to multiply it with some safety coefficient at the end, so the exact value doesn't matter.
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0.04 x 75 == 0.75 x 4 == 75 x 4 x 0.01
4*75/100
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That's a neat trick but also 4% of 75 = (1% of 75) * 4 = 0.75 * 4 = 1.5 * 2 = 3
Answer
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Ah, joy of commutative algebra.
Wait until you get to noncommutative algebra.. shudders. No one who mastered that monster of a subject is sane in any measure.
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Is it weird that I just went
start: 75
to actual decimal: .75
*2*2: 1.5 -> 3
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Even the first one, 0.75 doubled and then doubled again is hard?
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I only learned this a few months ago here on Lemmy and still don't believe it. It's magic. You think you're going to "get it" (trick it) this time, but nope! Still works somehow!
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0.75*4
I'd do 4%=1/25, 75/25=3.
Sure with easy numbers multiplication is easy. Try anything else.
75% = 3/4
(3/4) * 4 = 3
Why did no one ever teach me this?? Did I miss this day in class? I feel so silly. This is really useful.
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Yeah, this will be so helpful when I'm trying to figure out 20% of 36.23!
Look, move the decimal one to the left, you've now got 10%. Double that and you've got 20%. How often are y'all trying to find out percentages of nice even numbers like that?
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I also remember a somewhat sinister question: Using a knife, divide 3 apples among 4 people with the less possible cuts. 💀
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Just do (7-5)+(5-4)=3
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4% is 1/25. 75 is 3*25. so the answer is 3!
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4% is 4 in a hundred
75 is 3/4 of a hundred
4% of 75 is 3
639% of 1282.5
This only works in small cases.
The way I see it it makes simple sense:
X% of Y = X * Y/100
Y% of X = Y * X/100
As we know there is no significance to the order here so it is easy to see why they are equal.
No. Stop it. Just multiply them together. This is useless.
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