This is a simple division series; each number is one-half of the previous number.
In other terms to say, the number is divided by 2 successively to get the next result.
4/2 = 2
2/2 = 1
1/2 = 1/2
(1/2)/2 = 1/4
(1/4)/2 = 1/8 and so on.
3rd number is the sum of 1st and 2nd, 4th number is the sum of 2nd and 3rd, 5th number is the sum of 3rd and 4th and so on. Hence, missing number will be 29 + 47 = 76
This is an alternating repetition series, in which a random number, 61, is interpolated as every third number into an otherwise simple subtraction series. Starting with the second number, 57, each number (except 61) is 7 less than the previous number.
There is a simple pattern in this sequence: it begins with 0 and then the prime numbers are added to consecutive elements in ascending order I.e., 2 is added to the first element 3 is added to second element 5 is added to third element and so on. So, 0+2 = 2; 2+ 3 = 5; 5+ 5 = 10; 10+ 7 = 17; 17+ 11 = 28; 28+ 13 = 41.
This is an alternating addition and subtraction series. In the first pattern, 10 is subtracted from each number to arrive at the next. In the second, 5 is added to each number to arrive at the next.
There are three alternative series 2, 3, 4, ?? (consecutive numbers), 9, 8, 7 ?. (consecutive number in descending order), and 23, 25, 27, ? Hence, 7 will come in place of the missing number.
