if one person can clean carpets in 20 hours and the other can in 12 hours? How long will it take them to clean up the carpets together?

Question

Im asking this question so somebody could solve this problem for me in a short amount of period. The answer should be easy but i can't think so give me step by step solution

Answer 1

t represents the time working together

 

t/20 + t/12 = 1   Each does a fraction of the one job.

 

Can you solve for t and answer?