A man can do a job in 3 hours. A woman can do the same job in 2 hours. How long does it take them to complete the job when working together?
1 job / 3 hours + 1 job / 2 hours = 1 job / x hours
2/6 + 3/6 = 5/6 Together the job takes them 5/6 hour.
WOOOPS .... a little arithmetic error .... the answer is 6/5 hours.