Answer: 10 minutes
Step-by-step explanation:
Given : Three postal workers can sort a stack of mail in 20 minutes, 30 minutes, and 60 minutes, respectively.
Let T be the time taken by all of them when they working together.
Then , we have the following equation :-
Hence, the time taken by all of them when they working together = 10 minutes.
Answer:
im not sure but i think its 29%