A rock is strong from the top of a tall building. The distance in feet between the rock in the ground x seconds after it is their own is given by f(x)=-16x2-4x+ 382 how long after the rock is thrown is it 340 feet from the ground

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?