Question

There were 60 runners to start the race. In the first half of the race,1/3 of them dropped out. In the second half of the race,1/4 of the remaining runners dropped out. How many runners finished the race?

Answer 1

In the question, it is already given that the total number of runners in the race is 60 and out of them 1/3 dropped out in the first half. In the second half 1/4 of the remaining runners dropped out.
Now
Total number of runners in the race = 60
Number of runners that dropped out in the first half = 1/3 * 60
                                                                                   = 20
Number of runners remaining = 60 - 20
                                                 = 40
Number of runners dropping out in the second half = 40 * 1/4
                                                                                 = 10
Then the number of runners that finished the race = 40 - 10
                                                                                 = 30
Then 30 runners completed the race.

Answer 2

1/3 60 = 20 : 40 runners left : 1/4 40 = 10 : 30 runners left