21
24
24, they are going up in 3's, 13, 16, 19 and 18, 21 so next number is 24.
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.
3 The series is obtained by subtracting a number that reduces by 1 at each stage 18 - 5 = 13 13 - 4 = 9 9 - 3 = 6 6 - 2 = 4 4 - 1 = 3
18
The next number in the series 4, 12, 6, 12, 36, 18, 36
24 for each number you add 5 and then subtract 2. 19 plus 5 is 24.
The next number in the series 4-12-6-12-36-18-36.. is 108.
Since the numbers are going down be 5,4,3,2, the next number would be 3. It would be 3 because it would then go down by one.
18
53
18