There are 486 balloons that need to br blown up for the spring dance at school of there are 18 volunteer how many balloons would each volunteer need to blow up

Empty box + box + empty box fill in the box is equal to 30 how

Which one ? is the answer and how to find this answer

At oaknoll school, 90 out of 270 students on computers. what percent of students at oak knoll school do not own computers? round the nearest tenth of a percent.