An astronaut is working on a satellite 200 miles above the ground. What is the measure of BD⌢, the portion of Earth that the astronaut can see? Round your answer to the nearest tenth. (Earth's radius is approximately 4000 miles.)

Oscar and julie ashton are celebrating their 15th anniversary by having a reception hall. they have budgeted $4,500 for their reception. if the reception hall charges a $90 cleanup fee plus & 36 per person, find the greatest number of people that they may invite and still stay within their budget.

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?

How are algebraic expressions evaluated using substitution?