1.  What is Sonia's present age?

I. Sonia's present age is five times Deepak's present age. 

II. Five years ago her age was twenty-five times Deepak's age at that time.

A. I alone sufficient while II alone not sufficient to answer
B. II alone sufficient while I alone not sufficient to answer
C. Either I or II alone sufficient to answer
D. Both I and II are not sufficient to answer
E. Both I and II are necessary to answer

Answer: Option E

Explanation:

 I. S = 5D    D = S ....(i)
5

II. S - 5 = 25 (D - 5)    S = 25D - 120 ....(ii)

Using (i) in (ii), we get S = 25 x S - 120
5

4S = 120.

S = 30.

Thus, I and II both together give the answer. So, correct answer is (E).