Math is hard. Math is easy. Depending on your natural predilections, one of these statements will ring ever true.
The following viral Math problems went around the world and back, baffling and infuriating in equal measure.
See how many you can get and feel free to boast about it in the comments:
H/T Insider
Perhaps the reason for the viral nature of this problem is that there are in fact two correct solutions!
The first solution can be found by adding the equation and then combining the sum with the result of the previous equation eg.
“1 + 4 = 5”
“5 + 2 + 5 = 12”
“12 + 3 + 6 = 21”
“21 + 8 + 11 = 40“
The second solution involves multiplying the second number in the equation by the number you are adding it to eg.
1 + (4 x 1) = 5
2 + (5 x 2) = 12
3 + (6 x 3) = 21
8 + (11 x 8) = 96
ANSWER(S): 40 or 96.
Seems pretty obvious, no? Well, your answer may depend on where you went to school.
The modern order of mathematical operations (PEMDAS or BODMAS- Parentheses/Brackets, Exponents/Orders, Multiplication-Division, Addition-Subtraction, If the same precedence left to right) dictates:
“6 ÷ 2(2 + 1)”
“6 ÷ 2(3)”
“3(3)”
= 9
However, there was some controversy as it turns out many people had been taught a pre-1917 usage of the rules which is slightly different. When using those rules the answer becomes 1. An explanation of why can be found here.
Apparently, only 1 in 10 people can get the right answer to this question without using a calculator. “Apparently”.
As you’ll see, it’s just a matter of rounding the numbers up or down and then picking the nearest number (they give you answer options for fuck sake!).
So the question becomes:
“10 (15 + 25 + 40)”
“10 (80)”
“= 800”
So the answer is 936 as it is (clearly) closer to 800 than any other option.
People actually couldn’t get this? Are we sure?
This is an issue of method and whether the student simply used a different way of demonstrating the same principle. The teacher clearly thought not. The Internet disagreed.
Using repeated addition, the student was asked to calculate “5 x 3”. The student wrote “5 + 5 + 5 = 15”, but was marked wrong with the “answer” being “3 + 3 + 3 + 3 + 3 = 15”. But what’s the difference?
Similarly, the second question asks the student to find “4 x 6” using an array. The student wrote out an array with 6 rows and 4 columns, while the teacher claims the answer is four rows and six columns. The answer being = 24.
The difference is merely cosmetic and has very little to do with grasping the central teaching tenet.
Shared by Kenneth Kong, a Singapore TV host, this question apparently comes from a 5th grade-level math paper and is a somewhat infuriating logic puzzle.
Let’s analyze the statements and, by process of logical elimination, we can figure out the answer:
“I don’t know when your birthday is, but I know Bernard doesn’t know, either.” – Albert
Albert knows that if Cheryl had whispered to Bernard either “19” or “18” then Bernard would definitely know as there is only one date each for those numbers respectively (May 19 or June 18).
Therefore, if Albert’s first statement is true, Cheryl couldn’t have said to Bernard May or June either- thus eliminating half of the possibilities (we are left with July 14, July 16, August 14, August 15 and August 17)
We then go on to the second statement:
“I didn’t know originally, but now I do.” – Bernard
If Bernard now knows, we can be sure that Cheryl didn’t tell him “14” as there are still two options (July 14 and Aug 14). So we can eliminate those dates. That leaves us with three possible answers – July 16, August 15 and August 17.
Now the final statement:
“Well, now I know too!” – Albert
Using that same logic, for Albert to know as well the month must be July, as if Cheryl has told him August he would still have two options (August 15 and August 17).
Thus the answer is July 16.
A math(s?) problem from the UK now, and people more annoyed that it was set for 7-year-olds than the actual challenging nature of the problem.
It’s rather simple:
We simply say – People getting off the train (-19), people getting on the train (+17).
“-19 + 17 = 2”
“63 + 2”
“= 65”
Of course, this being the Internet, some people think the answer is 0 (nobody would be on the train to begin with) or 46 (the number of passengers on the train leaving the departure station).
It’s a trap!
There is no missing $1 – the wording is just intentionally confusing.
Let’s try and look at the total, not the debt owed.
Mum has $50 and Dad has $50 = $100
Mum gives you $50 and Dad gives you $50 + $100
The store takes $97 and gives back $3 = $100
The store has $97, You have $1, Mum has $1, and Dad has $1 = $100
Understand?
Me neither.
“More than 50% of students at Harvard, MIT, and Princeton got this question wrong” was the caption on this brainteaser, proving absolutely nothing other than not everyone at elite universities studies Math.
The instinctive response is to say the answer is 10 cents. Instinctively wrong! $1 is only 90 cents more than 10 cents, not a whole $1.
The correct answer is 5 cents becuse “$0.05 + $1.05 = $1.10”
A math problem that will test your patience more than your mathematical ability, this Vietnamese challenge asks you to use numbers 1-9 to make the equation equal 66 (the : are division signs).
The trick? There isn’t one. Just good old fashioned trial and error.
HINT: Write it out as a conventional equation and go from there.
The answer ca be found here
And finally, a Math problem that has nothing to do with Math at all.
You may have only 20 seconds to answer, but 20 seconds is a long time to simply flip the picture upside down.
The answer is 87.
