Poll
3 votes (13.63%) | |||
2 votes (9.09%) | |||
14 votes (63.63%) | |||
3 votes (13.63%) |
22 members have voted
Fwiw, whoever authored this has not yet confirmed their solution.
1+4=5
2+5=12
3+6=21
8+11=?
I do not know the author's original intent. But one correct answer is 201, and does not require manipulation of the equations as other solutions above do.
Each equation is in base 10. Each solution is in another base, diminishing by 1.
The first equation is expressed in base 10, answered in base 6. 5 in base 10= 5 in base 6.
The second is expressed in base 10, answered in base 5. 7 in base 10 is 12 in base 5.
The third is expressed in base 10, answered in base 4. 9 in base 10 is 21 in base 4.
The last equation, expressed in base 10, should be answered in base 3, to follow the pattern of previous answers. 19 in base 10 = 201 in base 3.
Is part of the answer to also come up with the next equation in the sequence?
The pattern appears to be the sum of the first 2 numbers + the result of the previous numbers... Thus:
4 + 7 = 11 (plus previous 21) = 32
5 + 8 = 45
6 + 9 = 60
7 + 10 = 77
8 + 11 = 96
..of course if you're not supposed to extrapolate, then it would be 19 + 21 = 40.
The '+' operator here does not signify addition, but is a more complex operation defined by the following:
a '+' b = (a X b) + a
So:
(1 x 4) + 1 = 5
(2 x 5) + 2 = 12
(3 x 6) + 3 = 21
(8 x 11) + 8 = 96
Quote: Romes
The pattern appears to be the sum of the first 2 numbers + the result of the previous numbers... Thus:
4 + 7 = 11 (plus previous 21) = 32
5 + 8 = 45
6 + 9 = 60
7 + 10 = 77
8 + 11 = 98
..of course if you're not supposed to extrapolate, then it would be 19 + 21 = 40.
Romes, are you saying that:
How is that???
Arithmetic error in typing =)...Quote: DocQuote: Romes
The pattern appears to be the sum of the first 2 numbers + the result of the previous numbers... Thus:
4 + 7 = 11 (plus previous 21) = 32
5 + 8 = 45
6 + 9 = 60
7 + 10 = 77
8 + 11 = 98
..of course if you're not supposed to extrapolate, then it would be 19 + 21 = 40.
Romes, are you saying that:77+8+11=98
How is that???
Quote: DocQuote: Romes
The pattern appears to be the sum of the first 2 numbers + the result of the previous numbers... Thus:
4 + 7 = 11 (plus previous 21) = 32
5 + 8 = 45
6 + 9 = 60
7 + 10 = 77
8 + 11 = 98
..of course if you're not supposed to extrapolate, then it would be 19 + 21 = 40.
Romes, are you saying that:77+8+11=98
How is that???
Because everything looks like 21 to romes. :)
Quote: Ayecarumba40. It appears the "total" is the sum of the equation + the prior answer.
Is part of the answer to also come up with the next equation in the sequence?
I might have titled it poorly. To my understanding, the question is simply to fill in the missing value in the 4th equation.
.Quote: JohnzimboI voted for 96 and agree with Joeman.
Here's the thing. Both 40 and 96 as solutions require you to manipulate the equations . There's no "x" on the left side of the equation, yet people are adding the solution of the previous equation to the next, either by changing the meaning of the addition sign, or by simple extrapolation.
To me, that's like saying 2+2=5 because you add 1 for it being first in the sequence. I see the logic of both progressions, but I think they violate the premise of the question.
Otoh, translating the right sides into a different base is also a manipulation, but it's not a false equivalency. So I think it's the most correct way to solve the problem.
I could be wrong. But that's why I asked the question.
the number to the right of the + is 3 higher than the number on the left of the +
the numbers increment sequentially as you go from line to line
the number to the right of the = is equal to the sum of the numbers to the left of the = plus the answer from the previous line.
extrapolating these things:
1 + 4 = 5
2 + 5 = 12
3 + 6 = 21
4 + 7 = 32
5 + 8 = 45
6 + 9 = 60
7 + 10 = 77
8 + 11 = 96
Quote: Dalex64I got what Romes got (after he corrected his arithmetic)
the number to the right of the + is 3 higher than the number on the left of the +
the numbers increment sequentially as you go from line to line
the number to the right of the = is equal to the sum of the numbers to the left of the = plus the answer from the previous line.
extrapolating these things:
1 + 4 = 5
2 + 5 = 12
3 + 6 = 21
4 + 7 = 32
5 + 8 = 45
6 + 9 = 60
7 + 10 = 77
8 + 11 = 96
And I agree with your extrapolation. But none of these equations except the first is true on its own. So how can this be a correct solution?
2 + 5 does not equal 12. Except in translating base higher than 5 to base 5.
Quote: beachbumbabs
And I agree with your extrapolation. But none of these equations except the first is true on its own. So how can this be a correct solution?
2 + 5 does not equal 12. Except in translating base higher than 5 to base 5.
there is also no indication which base the numbers are displayed in, or if that base should be changed between equations, either.
these sorts of problems which appear on facebook and the like tend to redefine what the symbols mean. I think someone mentioned that the answers are a running subtotal, as if you were hitting the subtotal button ⋄ on an adding machine each time you see the = sign.
That's true if + means the binary addition operator, but if + just means "and" and the real phrasing of the question is "1 and 4 = 5; 2 and 5 = 12; etc." then the question can be rephrased as "Here are three datapoints for x, y, and f(x,y). Find f(8,11)." That's relatively easy:Quote: beachbumbabsAnd I agree with your extrapolation. But none of these equations except the first is true on its own. So how can this be a correct solution?
2 + 5 does not equal 12. Except in translating base higher than 5 to base 5.
I mean, obviously 2+5 does not equal 12, so you can't just take those first three lines at face value or you'd be stuck with "well, 2+5 != 12 so the whole problem is wrong." But IMO it would be dirty pool to create a math problem where the radix changed mid-problem. That'd be like me offering to buy your car for $100000, you agreeing, and then I show up with $32 and demand you hand me the keys.
As is typical with such Internet questions, there isn't enough information given to arrive at a unique solution while discarding all the others.
- Perform multiplication instead of addition and
- add '1' to the second term
resulting in
- 1+4 --> 1*5 = 5
- 2+5 --> 2*6 = 12
- 3+6 --> 3*7 = 21
- 8+11 --> 8*12 = 96
I can't take credit though. My wife looked at it and had the answer in~ 3 seconds. She can be scary that way.
Whats really weird is that there are multiple algorithms that give the same result (i.e. Romes and Joeman)
Quote: beachbumbabs
I do not know the author's original intent. But one correct answer is 201, and does not require manipulation of the equations as other solutions above do.
Each equation is in base 10. Each solution is in another base, diminishing by 1.
The first equation is expressed in base 10, answered in base 6. 5 in base 10= 5 in base 6.
The second is expressed in base 10, answered in base 5. 7 in base 10 is 12 in base 5.
The third is expressed in base 10, answered in base 4. 9 in base 10 is 21 in base 4.
The last equation, expressed in base 10, should be answered in base 3, to follow the pattern of previous answers. 19 in base 10 = 201 in base 3.
1 + 4 = 5 => 5 in base 5
2 + 5 = 7 => 12 in base 5
3 + 6 = 9 => Aimee21 in base 4
8 + 11 = 19 => 103 in base 4
Quote: TumblingBonesThe answer is
96. The algorithm is
- Perform multiplication instead of addition and
- add '1' to the second term
resulting in
- 1+4 --> 1*5 = 5
- 2+5 --> 2*6 = 12
- 3+6 --> 3*7 = 21
- 8+11 --> 8*12 = 96
I can't take credit though. My wife looked at it and had the answer in~ 3 seconds. She can be scary that way.
Quote: MathExtremistthe question can be rephrased as "Here are three datapoints for x, y, and f(x,y). Find f(8,11)."
You are perfectly correct that "4+7=32" is another valid datapoint in the set (i.e., f(4,7)=32).
The solution to each equation is the product of the two numbers plus the smaller one. The order of the equations is irrelevant.
1 x 4 + 1 = 5
2 x 5 + 2 = 12
3 x 6 + 3 = 21
8 x 11 + 8 = 96
x+y = f(x,y) = SUM[x, y, f(x-1, y-1)] where X > 0 OR Y > 0
-3+0 = -3
-2+1 = -1-3 = -4
-1+2 = 1-4 = -3
0+3 = 3-3 = 0
1+4 = 5+0 = 5
2+5 = 7+5 = 12
3+6 = 9+12 = 21
4+7 = 11+21 = 32
5+8 = 13+32 = 45
6+9 = 15+45 = 60
7+10 = 17+60 = 77
8+11 = 19+77 = 96
Using f(x,y) = x*(y+1) method:
f(8,11) = 8*(11+1) = 8*12 = 96
Like ME said -- there are many formulas that lead to the same answer....or that at least follow the pattern.
BTW, 5 does not exist in base 5.
5 in decimal is 10 in base-5: 1*5^1 + 0*5^0 Just like 2 in decimal is 10.
https://www.youtube.com/watch?v=-HFwok9SlQQQuote: odiousgambitif there is no official answer, then this math exercise is perfect for the Millennials. Everybody is right and and we all get a trophy for participating!
96.
Each number of the right side of the equation equals x*(y+1), where x is the first number and y is the second.
8*(11+1) = 96
Quote: RSUsing the subtotal method:
x+y = f(x,y) = SUM[x, y, f(x-1, y-1)] where X > 0 OR Y > 0
-3+0 = -3
-2+1 = -1-3 = -4
-1+2 = 1-4 = -3
0+3 = 3-3 = 0
1+4 = 5+0 = 5
2+5 = 7+5 = 12
3+6 = 9+12 = 21
4+7 = 11+21 = 32
5+8 = 13+32 = 45
6+9 = 15+45 = 60
7+10 = 17+60 = 77
8+11 = 19+77 = 96
Using f(x,y) = x*(y+1) method:
f(8,11) = 8*(11+1) = 8*12 = 96
Like ME said -- there are many formulas that lead to the same answer....or that at least follow the pattern.
Thanks for making me feel less than knowledgable. I just looked for a pattern and came up with 96.
Quote: Romeshttps://www.youtube.com/watch?v=-HFwok9SlQQ
[video says there is no 'Millennials' generation ]
I may be stepping on some toes to rag on the M-gen, so from now on I will pick on Generation Z ....... LOL