Answer: They were marching for 32 minutes.
Step-by-step explanation: If you multiply the 4/5 times by 60 minutes (1 hour), then you will get 48 minutes. 48 minutes is the time of the band practice. Once you get that, then multiply that by 2/3 to get the amount of minutes marching. Once you multiply 2/3*48, you will get 32, which is how many minutes they were marching during band practice.
Im not 100% sure if it’s right but i think you do
pi x r^2 which means pi x 12^2 =452.3893421(if you round it in 2dp its 452.39)
If you need the volume then you times it by 35.
