If 28 men complete the $$ {7\over 8}$$ portion of a work in a week, then how many man will have to work to complete the remaining work in one finish.

A man is twice as fast as women and woman is twice fast as a boy. If all of them i.e., a man, a woman and a boy can finish a work together in 4 days, in how many days will a boy do it alone?

A can built a wall in 8 days while B can destroy the same wall in 3 days. A start the work and worked for 6 days, during the last 2 days of which B also joins him. In how many days A can finish the remaining work alone?

A and B can together complete a piece of work in 18 days. B and C can together complete the same work in 24 days and A and C can together complete it in 36 days. In how many days can A. B and C, working together, complete this piece of work?

A is twice as good a workman as B and B is twice as good a workman as C. If A and B can together finish a piece of work in 4 days, then C can do it by himself in : 

A can do a work in 24 days and B is 20% more efficient than A. If C can do the work in 10 days more than B, then find the days taken by A and C together to complete the work.

B is 20% more efficient than A. A started the work and work for x days and then A is replaced by B. B completed the remaining work in x+8 days. Ratio of the work done by A and B is 2:3. In how many days A and B working together can complete the whole work?

Direction : Each of the questions below consists of a question and two statements numbered I and II are given below it. You have to decide whether the data provided in the statements are sufficient to answer the question. Read both the statements and
Give answer
(A) If the data in statement I alone are sufficient to answer the question, while the data statement II alone are not sufficient to answer the question.
(B) If the data in Statement II alone are sufficient to answer the question, while the data in statement I alone are not sufficient to answer the question.
(C) If the data in statement I alone or in Statement II alone are sufficient to answer the question.
(D) If the data in both the statement I and II are not sufficient to answer the question.
(E) If the data in both the statement I and II together are necessary to answer the question.

 In how many days can be B alone complete the work?
I. B and C together can complete the work in 8 days.
II. A and B together can complete the work in 12 days.