Can You Solve The Day Of The Week Riddle?
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Okay, pay attention. This logic puzzle might rattle your brain. Here is the day of the week riddle, as presented by Presh Talwalkar of the MindYourDecisions YouTube channel: When the day after tomorrow is yesterday, then today will be as far from Wednesday as today was from Wednesday when the day before yesterday was tomorrow. What day is today? Check out the video below to learn how to solve this brain teaser, or scroll down to read the answer. Good luck!
from MindYourDecisions
Can You Solve This Order Of Operations Problem With 7s?
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The beautiful thing about math is that it's cut and dry, black and white, right and wrong—well, most of the time. With problems that require indepth knowledge of the order of operations, a seemingly simple algebra problem can become insanely frustrating. Here's an example of such a problem that was presented on YouTube by Presh Talwalkar, the host of the MindYourDecisions math channel. It goes as follows: 7 + 7 ÷ 7 + 7 × 7  7 = ? Watch the video below for the solution, or read the answer by scrolling down.
from MindYourDecisions
Comparing Infinities Can Give You Counterintuitive Results
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The concept of infinity is infinitely fascinating. But before we really get into some mindboggling number stuff, it's important for you to first understand this: There is more than one kind of infinity. In fact, there are infinite infinities, and some infinities are bigger than others. And when it comes to comparing infinities, the results can seem rather counterintuitive. Here's an example: There can be just as many numbers between 0 and 1 as there are between 0 and 2.
from Undefined Behavior
This Puzzle Asks You To Find The Best Size For A Soup Can
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The optimal soup can puzzle is a fun mathematical exercise, but it also has realworld applications. For those in manufacturing and packaging, consideration needs to be used in determining the lowestcost way to manufacture products, which means using the smallest amount of material necessary. Give it a try yourself in this problem from Presh Talwalkar of the MindYourDecisions YouTube channel: You need a can that can hold volume V. Three can options all hold the same volume V: one is short and wide, one is equally tall as it is wide, and one is tall and narrow. Which can uses the least material? Watch the video below to learn how this problem is solved, or scroll down to get the answer.
from MindYourDecisions
Mentally Calculate The Day Of Any Date With The Doomsday Rule
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When someone professes to have a photographic memory, the first thing many people ask them is to name the day of the week on which a random date landed. Often, they do it easily, and everyone around is sufficiently impressed with their memory. Unfortunately—or fortunately, for those without such a gift—naming the day of the week of a date doesn't require a photographic memory; just some quick mental arithmetic. Anyone can do it using the doomsday rule, a simple algorithm devised by mathematician John Horton Conway.Related: Should The Year Have 13 Months?
from MindYourDecisions
Key Facts to Know

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Simply typing a date into the website WolframAlpha can tell you which day of the week it falls/fell on. 0:08

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The doomsday rule states that certain days of the year will always fall on the same day. 0:50