TheSAT examallows for about two hour to work out eachmath problem . The key to conquering the mathematics section of the test is knowing how to bust down a on purpose puzzling question and sift through unnecessary details to quickly find the reply .
In a Quora thread of the most difficult SAT math problems , one interrogative come forth as " the meanspirited trial trouble ever . "
It translate :
The SAT math question.MindYourDecisions/YouTube
In a class ofpstudents , the mediocre ( arithmetic mean value ) of the exam score is 70 .
In another class ofnstudents , the average of the scores for the same test is 92 .
When the sexual conquest of the two classes are mix , the average of the test scores is 86 .
What is the value ofp / n ?
Can you count on out how to work it ?
If not , do n’t fear — Presh Talwalkar , a math whiz who wrote the record book " The Joy of Game Theory : An instauration to Strategic Thinking " and tackles math query and riddles on hisYouTube channelandblog , both call MindYourDecisions , divvy up a stride - by - step root to this notoriously tough problem .
There are a few way to solve it , but Talwalkar present a wide-eyed crosscut .
The first course of study had an norm of 70 . That ’s 16 points below the average score of 86 . In other words , 86 - 70 = 16 . Since there arepstudents in the form , the difference from the average is 16p .
The 2nd class had an norm of 92 . That ’s 6 point more than the norm of 86 . In other run-in , 92 - 86 = 6 . There are n educatee in this category , so the conflict from the average is 6n .
Because these classes average out out together — as the problem say " when the score of the two grade are combined " — the deficit of power point has to be equal to the nimiety of points . Therefore , 16pis adequate to 6n .
Turning that into an equation , we can easily figure out whatp / nis :
16p= 6n
p / n= 6/16 , or 3/8
Still stumped ? you’re able to watchTalwalkar ’s full account of the solutionbelow orread more on his blog .
understand next on Business Insider : A relationship therapist breaks down the 10 most common fights couples have
