1.  A is thrice as good as workman as B and therefore is able to finish a job in 60 days less than B. Working together, they can do it in: 

Answer: Option B Explanation: Ratio of times taken by A and B = 1 : 3. The time difference is (3  1) 2 days while B take 3 days and A takes 1 day. If difference of time is 2 days, B takes 3 days.
So, A takes 30 days to do the work.
