In a 300 m race A beats B by 22.5 m or 6 seconds. B's time over the course is:

To find B's time over the course, we first need to understand the relationship between A and B.

1. We know that A beats B by 22.5 m in a 300 m race. This means that when A runs 300 m, B runs 300 m - 22.5 m = 277.5 m.

2. We also know that A beats B by 6 seconds. This means that B takes 6 seconds longer than A to run the race.

3. The time it takes A to run 22.5 m (the distance by which A beats B) is given as 6 seconds.

4. Therefore, the time it takes B to run the full 300 m race is the time it takes A to run 277.5 m plus the extra 6 seconds it takes B to run the remaining 22.5 m.

5. We can set up a proportion to find the time it takes A to run 277.5 m: (22.5 m / 6 sec) = (277.5 m / x sec)

6. Solving for x gives us x = (6 sec * 277.5 m) / 22.5 m = 74 seconds.

7. Adding the extra 6 seconds it takes B to run the remaining 22.5 m gives us a total time of 74 sec + 6 sec = 80 seconds.

So, B's time over the course is 80 seconds.