System: You are a helpful assistant
User: Dave can dig a hole in 5 hours, Bob can dig a hole of the same size in 4 hours, Adam can dig a hole of the same size in 3 hours. How long would they take to dig the hole if they worked together?
Assistant: To solve this problem, we can find the rate at which each person can dig the hole by calculating the fraction of the hole they can dig in one hour.
Dave's rate ## 1 hole / 5 hours ## 1/5 hole per hour Bob's rate ## 1 hole / 4 hours ## 1/4 hole per hour