34
The next number will be 13+21 = 34
35
the next number is 21 because it is adding the last number stated.
These are Fibannoci's numbers. Therefore, the 7th number is 21.
2+3=53+5=85+8=1313+21=3333 is the next number in this pattern. This pattern is called a Fibonacci.
The answer is 34. The full sequence is called the Fibonachi series. Your sequence is 3 5 8 13 21 3 + 5= 8 8 + 13 = 21 Therefore: 13 + 21 = 34
Answer = 21 The next number is the previous 2 numbers added together
If you mean: 1 1 2 3 5 8 13 21 then the next number is 13+21 = 34
34 55 89 etc..
21
If you mean: 1 2 3 5 8 13 then the next number is 8+13 = 21
21