Answer: 8
Explanation:
Out of a total of 80 runners, during First half: 2/5 of 80 dropped out
ie (2/5) of 80
= 0.4 x 80 = 32
Of the 32 remaining runners, during Second half 1/4 dropped out
i.e (1/4) of 32
= 0.25 x 32 = 8
Thus, only 8 runners finished the race.