24, they are going up in 3's, 13, 16, 19 and 18, 21 so next number is 24.
21 - each number in the series increases by the series 1,2,3,4,5.... Whereby 6 and 7 are separated by 1, 7 and 9 are separated by 2, 9 and 12 are separated by 3, 12 and 16 are separated by 4, so the next in the series would be 21 (16 and 21 are separated by 5).
16 to 26 (+10) 26 to 21 (-5) 21 to 31 (+10) 31 (-5) = 26 26
13 18 16 21 19 24 22 27 25 ... . This series consists of adding 5 to the first number and subtracting 2 from the next number, repeating the sequence in that order.
The rule is: add 5, subtract 2, add 5, subtract 2, . . . Next number is 24.
24
24, they are going up in 3's, 13, 16, 19 and 18, 21 so next number is 24.
21 - each number in the series increases by the series 1,2,3,4,5.... Whereby 6 and 7 are separated by 1, 7 and 9 are separated by 2, 9 and 12 are separated by 3, 12 and 16 are separated by 4, so the next in the series would be 21 (16 and 21 are separated by 5).
16 to 26 (+10) 26 to 21 (-5) 21 to 31 (+10) 31 (-5) = 26 26
16+10= 26 26-5= 21 21+10= 31 31-5= 26 The answer is 26
16+10=26 26-5=21 21+10=31 31-5=26 26+10=36
13 18 16 21 19 24 22 27 25 ... . This series consists of adding 5 to the first number and subtracting 2 from the next number, repeating the sequence in that order.
The rule is: add 5, subtract 2, add 5, subtract 2, . . . Next number is 24.
16 21 22 29
21
24 for each number you add 5 and then subtract 2. 19 plus 5 is 24.
The next number is -21