Telephone number

[ov25]

In the telephone number 936-215X, what digit does X represent?

(1) Only one digit in the telephone number is greater than X.
(2) X is the greatest of the digits not among the telephone number's first six digits.

[Rahul@gurome]

In the telephone number 936-215X, what digit does X represent?

(1) Only one digit in the telephone number is greater than X.
(2) X is the greatest of the digits not among the telephone number's first six digits.

Given: 936-215X is a telephone number, where X is a digit.

Statement 1: Only one digit in the telephone number is greater than X.
Thus,

• (1) If X is 9, then there is no digit in the telephone number which is greater than X (= 9).
  (2) If X is less than or equal to 5, then there will be two digits (6 and 9) greater than X.

Therefore X is either 6 or 7 or 8.

Not sufficient.

Statement 2: X is the greatest of the digits not among the telephone number's first six digits.
Digits that are not in the telephone number are: 0, 4, 7 and 8. Greatest among them is 8. Thus X is 8.

Sufficient.

The correct answer is B.