question_answer

Which information are necessary to answer the questions asked-

x, y and z together will finish the work in how many days?

(I)   x does half as much work as y and y does half as much work as x and z does together in one day.

(II) y does the whole work in 40 days.

(Ill) x and z do the whole work in 20 days.

A)  Only I or. II or III

B)  Either I and II or I and III

C)  Only II and III

D)  All are necessary

E)  None of these