Answer:
Step-by-step explanation:
You are going to choose 4 books in any order.
Four = 12! /(8!4!) Remember that order doesn't matter, so we have 12C4
495
74000-10%x
A. 9.49
Use Pythagorean theorem to find the distance and make a right triangle.
So then..
a² + b² = c²
3² + 9² = c²
c² = 9 + 81
c² = 90
c² =
c = 9.49