There were 80 runners to start a race. In the first half of the race, 1/4 of them dropped out. In the second half of the race, 2/5 of the remaining runners dropped out. How many runners finished the race?

36 runners finished the race.

Step-by-step explanation:

In the first half of the race, 1/4 of them dropped, so we need to calculate 1/4 of 80:

(1/4) * 80 = 80/4 = 20

If 20 runners dropped out, now we have 80 - 20 = 60 runners.

Then, in the second half, 2/5 of the remaining runners dropped out, so:

(2/5) * 60 = 2*60/5 = 120/5 = 24

If 24 runners dropped out, now we have 60 - 24 = 36 runners.

So, 36 runners finished the race.