How many days are needed for A to complete a piece of work?
I) A and B require 20 days to complete the work
II) A takes 20 days more than B to complete the work

A

if the statement I alone is sufficient to answer the question.

B

if the statement II alone is sufficient to answer the question.

C

if the statements I and II together are sufficient to answer the question but neither statement alone is sufficient.

D

if both the statements I and II together are not sufficient to answer the question and additional data is required.