Solve the problem.A ball is thrown upward with an initial velocity of 21 meters per second from a cliff that is 
high. The height of the ball is given by the quadratic equation 
where h is in meters and t is the time in seconds since the ball was thrown. Find the time that the ball will be 30 meters from the ground. Round your answer to the nearest tenth of a second.
A. 7.6 seconds
B. 7.5 seconds
C. 7.0 seconds
D. 6.9 seconds
Answer: D
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Solve the problem.By walking src="https://sciemce.com/media/4/ppg__rrr0709190917__f1q37g6.jpg" alt="" style="vertical-align: -4.0px;" />
A. 5 hr
B. 3 hr
C. 2 hr
D. 1 hr
for one period of time and 
for another, Roger traveled 
Had he walked 
faster throughout, he would have 
miles. How many hours did he walk at
Solve the problem.A couple who wants to purchase a home with a price of $325,000 has $100,000 for a down payment. If they can get a 25-year mortgage at 8% per year, paid on the unpaid balance, what is the total amount they will pay before they own the house outright? How much interest will they pay over the life of the loan?
A. $852,520; $527,520 B. $752,520; $427,520 C. $620,977; $295,977 D. $520,977; $195,977
Solve.The amount of paint needed to cover the walls of a room varies jointly as the perimeter of the room and the height of the wall. If a room with a perimeter of 40 feet and 
walls requires 
of paint, find the amount of paint needed to cover the walls of a room with a perimeter of 55 feet and 10-foot walls.
A. 5.5 quarts B. 11 quarts C. 55 quarts D. 550 quarts
For the pair of functions, find the indicated domain.f(x) = 
, g(x) = 3x + 15Find the domain of f ? g.
A. (-?, ?) B. (-?, -5] ? [0, ?) C. [-5, ?) D. [0, ?)