In a 300 m race, P beats Q by 22.5 m or 6 seconds. What is Q's time over the course?

Let $$v_Q$$ be Q’s speed in metres per second (m s−1).

We are told that after P has finished the entire $$300\text{ m}$$, Q is still $$22.5\text{ m}$$ behind and needs another $$6\text{ s}$$ to cover that remaining distance.

Hence, the speed of Q is obtained directly from

$$v_Q = \frac{\text{distance}}{\text{time}} = \frac{22.5}{6} = 3.75\text{ m/s}$$

Q’s total time to run the full $$300\text{ m}$$ is therefore

$$T_Q = \frac{300}{v_Q} = \frac{300}{3.75} = 80\text{ s}$$

Thus, Q completes the course in 80 seconds.

Option A which is: 80 seconds