A toy train set includes a train station building which is a scale model of a real building. The area of the front side of the toy building is 1 square foot. The real building's front side has
an area of 400 square feet. If we view the real building as a dilation of the toy, what is the
scale factor?

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?