#### Answer

6.00 m/s.

#### Work Step by Step

Find the time for the sound to travel from the pins to the bowler.
$t = \frac{(16.5 m)}{(340 m/s)} = 0.0485 s.$
Therefore the time that the ball took to go from the bowler to the pins is the difference between 2.80 and that time, 2.7515 s.
$$v = \frac{16.5 m}{2.7515 s} = 6.00 m/s$$