Heyy im really bored anyone wanna talk

Gregory draws a scale drawing of his room. the scale that he uses is 1 cm : 4 ft. on his drawing, the room is 3 centimeters long. which equation can be used to find the actual length of gregory's room?

65% of students in your school participate in at least one after school activity. if there are 980 students in you school, how many do not participate in an after school activity?

Could somebody me with this radical simplification?