6 gives largest output and 12.7 or -.4 gives the smallest
D. 663 square meters is the anwser
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.