i am between 21 and 34 you say name when you count by fives from zero

mmmmmhh, how about 25 ?

10

To count by fives from zero, you would start at zero and add 5 each time. Let's go through the counting process:

0 + 5 = 5
5 + 5 = 10
10 + 5 = 15
15 + 5 = 20
20 + 5 = 25
25 + 5 = 30
30 + 5 = 35

Based on this counting, you fall within the range of 21 to 34. Therefore, the number you mention when counting by fives from zero is 25.