help me to solve this sequence please: 2, 2, 16, 18, 80, 86, X
- Thread starter N13AR
- Start date
I have no idea what is being look for but just to have fun:
To get started, all numbers before the first one are assumed to be zero but are otherwise not part of the sequence.
Odd numbers are a random number larger than the last one in the sequence. Even number are the sum of the number before them and the units digit of third number before them.
Number 1: 2, a random number larger than zero
Number 2: 2 = 2 + 0, i.e. all numbers before Number 1 are assumed zero.
Number 3: 16, a random number larger than 2.
Number 4: 18 = 16 + 2, the number before it (16) plus the units digit of the third number back (units digit of 2).
Number 5: 80, a random number larger than 18.
Number 6: 86 = 80 + 6, the number before it (80) plus the units digit of the third number back (units digit of 16).
Number 7: X, a random number larger than 86.
To get started, all numbers before the first one are assumed to be zero but are otherwise not part of the sequence.
Odd numbers are a random number larger than the last one in the sequence. Even number are the sum of the number before them and the units digit of third number before them.
Number 1: 2, a random number larger than zero
Number 2: 2 = 2 + 0, i.e. all numbers before Number 1 are assumed zero.
Number 3: 16, a random number larger than 2.
Number 4: 18 = 16 + 2, the number before it (16) plus the units digit of the third number back (units digit of 2).
Number 5: 80, a random number larger than 18.
Number 6: 86 = 80 + 6, the number before it (80) plus the units digit of the third number back (units digit of 16).
Number 7: X, a random number larger than 86.
i did kinda reach to that conclusion, but this question is taken from a math book for 15 years old students, so i don't think the answer is supposed to include randomness
It would be interesting to find out what is expected. Of course one can give a rational for any random number one wants for the next number in the sequence, in fact probably several.
(2-2)=0 ----> 2^1 - 2
(16-2)=14 -----> 2^4 - 2
(18-16)=2 ----- >2^2 - 2
(80-18)=62 -----> 2^6 - 2
(86-80)=6 -----> 2^3 - 2
(x-86) = 2^8 - 2 -------> x=342
just a random try
Hey, I like that better than mine. At least it isn't random.