Can somebody please help me

What percent of 18 is 24? and plz explain thx.

Find the area of the region that is inside r=3cos(theta) and outside r=2-cos(theta). sketch the curves.

Aclassroom is made up of 11 boys and 14 girls. the teacher has four main classroom responsibilities that she wants to hand out to four different students (one for each of the four students). if the teacher chooses 4 of the students at random, then what is the probability that the four students chosen to complete the responsibilities will be all boys?