21
14
It is 11 which is also a prime number
It is 12 because 3*6*12 = 216.
3, 6, 9, 12, and 13
(12/13)x = 20x = 20 / (12/13) = (20 x 13) / 12 = 21 and 2/3
14
This missing number is 5
It is 11 which is also a prime number
13/16 3+9=12 4+8=12 12 is divisible by 3 39/3=13 48/3=16 13/16 can not both be divided by the same number (13 is a prime number)
It is 12 because 3*6*12 = 216.
The missing number is 1321!!! Simple Fibonacci row! 0+1=1 1+1=2 1+2=3 2+3=5 3+5=8 5+8=13 8+13=21 13+21=34 ......
6
1 2 3 4 5 6 7 8 9 10 11 12 13. Could not be simpler!
3, 6, 9, 12, and 13
(12/13)x = 20x = 20 / (12/13) = (20 x 13) / 12 = 21 and 2/3
13 is one such number.
The missing number in the sequence "011235813" corresponds to the Fibonacci series, which is generated by adding the two previous numbers to get the next one. The sequence starts with 0, 1, 1, 2, 3, 5, 8, 13, and the next number after 13 is 21. Therefore, the complete sequence with the missing number included would be "01123581321."