At a school, 40% of the sixth-grade students said that hip-hop is their favorite kind of music. If 100 sixth-grade students prefer hip-hop music, how many sixth-grade students are at the school? Explain and show your reasoning.

Julius went on a volunteer trip to centralamerica and took medical supplies with him.he packed a bag with 50 pounds of supplies.he brought pieces of equipment that weighed10 pounds each and bottles of medicine thatweighed pound each prepresents thenumber of pieces of equipment he broughtand b represents the number of bottles ofmedicine he brought then the total weight canbe represented by the equation 10p+b 50.the brought 3 pieces of equipment, how manybottles of medicine did he bring?