In a class,24 students read physics,21 students read Maths and 9 students read both physics and maths. if each student read at least one of the two subjects ,find the number of the students in the class

You are saving to buy a bicycle; so far you save 55.00. the bicycle costs 199.00. you earn 9.00 per hour at your job. which inequality represents the possible number of h hours you need to work to buy the bicycle?