Problems on Ages - General Aptitude

Each of these questions is followed by three statements. You have to study the question and all the three statements given to decide whether any information provided in the statement(s) is redundant and can be dispensed with while answering the given question.
Q1:

What is the difference between the present ages of Ayush and Deepak?
I.  The ratio between Ayush's present age and his age after 8 years 4 : 5.
II.  The ratio between the present ages of Ayush and Deepak is 4 : 3.
 III.  The ratio between Deepak's present age and his age four years ago is 6 : 5.

A Any two of I, II and III

B I or III only

C Any one of the three

D All I, II and III are required

E Even with all I, II and III, the answer cannot be obtained.

ANS:A - Any two of I, II and III

Clearly, any two of the given statements will give the answer and in each case, the third is redundant.