Architectural Designers is creating a schematic for a bridge over the Columbia River whose arch is in the shape of a parabola. The road, 40 feet above the river surface, represents the directrix of the parabolic arch. The focus of the parabolic arch is located 20 feet above the river surface. In the schematic, the river surface will be positioned along the x-axis and the axis of symmetry for the downward opening parabolic arch will be positioned along the y-axis. Which equation best models the parabolic arch in the schematic? A. y=0.025x^2+30
B. y=-0.025x^2+10
C. y=-0.025x^2+30
D. y=0.025x^2+10

The krasnapolski is a top-of-the-line hotel in amsterdam, the netherlands. among their many services, they rent bicycles to guests. the bicycle checkout is open 24 hours per day 7 days per week and has 50 bicycles on hand. on average, 10 guests request a bicycle each day, arriving completely randomly at all times of the day during the spring and summer seasons. guests keep bicycles for four days on average, with a standard deviation of two days. how long does a guest on average have to wait for a bike? a. approximately 24 hours b. approximately 0.033 hours c. approximately 4 days d. approximately 47 minutes