Each of the questions given below consists of a question followed by three statements. You have to study the question and the statements and decide which of the statement(s) is/are necessary to answer the question.

1

What is the two-digit number?
I.
Sum of the digits is 7.
II.
Difference between the number and the number obtained by interchanging the digits is 9.
III.
Digit in the ten's place is bigger than the digit in the unit's place by 1.

What is the two-digit number?
I.
The difference between the two-digit number and the number formed by interchanging the digits is 27.
II.
The difference between the two digits is 3.
III.
The digit at unit's place is less than that at ten's place by 3.

A.

I and II only

B.

I and III only

C

All I, II and III

D.

I, and either II or III

E.

Even with all I, II and III, answer cannot be give.