Hi, I have been trying to figure this one math problem for awhile and I am stuck. I believe the answer is between A or B.

Question

Skip is practicing tennis serves against a wall. The distance between Skip and the tennis ball, in feet, at any time T, measured in seconds, is D(T)=-1.5(T-8)+9. which analysis of the formula is true?
A. Skip is 9 feet from the wall and the ball will return to him in 1.5 seconds.
B. Skip is 9 feet from the wall and the ball will return to him in 12 seconds.
C. Skip is 8 feet from the wall and the ball will return to him in 1.5 seconds.
D. Skip is 8 feet from the wall and the ball will return to him in 9 seconds.

Answer 1

This is strange.
D(0) = 21
D(8) = 9
D(14) = 0

I am having a hard time relating T values with travel time. Does he server the ball at T=0? Can't be, since then he is 21 ft from the ball.

The distance is always decreasing, so clearly the equation describes the return trip from somewhere.

Does the ball bounce off the wall at T=0? None of the choices says the wall is 21 ft away.

Maybe you can sort things out.