21 vote
A man can do a job in 10 days. His father takes 15 days and his son finishes it in 20 days. How long will they take to complete the job if they all work together?
A man can do a job in 10 days. His father takes 15 days and his son finishes it in 20 days. How long will they take to complete the job if they all work together?
1). 60/13 days
2). 13/60 days
3). 19/25 days
4). 25/19 days
2 answers
22 vote
Work done by the man in 1 day = 1/10
Work done by the father in 1 day = 1/15
Work done by the son in 1 day = 1/20
Work done by them together in 1 day = 1/10 + 1/15 + 1/20 = (6 + 4 + 3) /60 = 13/60
Time taken by them to complete the job = 60/13 days
22 vote
A man can do job in 10days His father do it in 15days . and his brother finished it in 20 days. They worked together for two days , the man left the job and his father left the job a day earlier than the completion of work the no. of days for which the work carried a out