According to the question, Xiao Qiang can beat the ball three times per second, that is, his speed of beating the ball is 3 balls per second. Xiao Yu can bounce the ball once in 2 seconds, that is, her speed is 1/2 ball/second. In order to hit the ball 100 times, you need to calculate how long Xiao Qiang and Xiao Yu each need to hit the ball.
Suppose Xiao Qiang takes t seconds, then Yu needs to take 100-t seconds. Therefore, the total time of bouncing the ball is:
t +(100 - t) = 100
After simplification: t = 50.
Therefore, Xiao Qiang needs to bounce the ball for 50 seconds and Xiao Yu needs to bounce the ball for 50 seconds. The number of small racket balls is:
3 balls per second × 50 seconds = 150 balls
The number of times Xiaoyu beats the ball is:
1/2 balls/s x 50 seconds = 25 balls
Therefore, it took Xiao Qiang 50 seconds to bounce the ball and Xiao Yu 50 seconds to bounce the ball.