Eight workers dug 3/8 of a tunnel in 10 days. If they need to finish the remaining 5/8 of the tunnel

Eight workers dug 3/8 of a tunnel in 10 days. If they need to finish the remaining 5/8 of the tunnel in 3 & 1/3 days, how many more workers must they hire?

Eight workers * 10 days = 80 days for one worker

If 3/8 of a tunnel took 80 days for one worker, then each 1/8 of a tunnel takes a single worker:
80/3 = 26 & 2/3 days

Multiply by 5 for the remaining 5/8 and we get:
133 & 1/3

We need 133 & 1/3 / 3 & 1/3 = 40 workers needed

Additional workers = Workers Needed - Original Workers
Additional workers = 40 - 8
Additional workers = 32