How to calculate the percentage of the sample in grouped data?

age group

[0,10) Frequency 9

[10,25) Frequency 27

[25,65] Frequency 54

n=90



What percentage of the sample falls [15,35)?How to calculate the percentage of the sample in grouped data?
Percentage can be calculated by frequency divided by total.



(0, 10); 9 / 90 = 10%

(10, 25); 27 / 90 = 30%

(25, 65); 54 / 90 = 60%