Can someone me with this question (beth and lewis buy the same amount of fish pellets. if beth feeds her goldfish 14fish pellets each day a container of pellets will last 20 days if lewis feed his fish 8 fish pellets each day how many more days will the container of pellet last lewis goldfish? )also show your work

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?