Each of the questions below consists of a question and two statements numbered I and II given below it. You have to decide whether the data provided in the statements are sufficient to answer the question.
What is Suman's rank from the top in a class of forty students?
I. Suman is 3 ranks below Deepak from the top.
II. Deepak's rank from the bottom is 23.
III. Suman is 3 ranks above Deepak from the bottom.

Options

A. Any two of the three
B. Only I and II
C. Only II and III
D. All I, II and III

Answer

D

Explanation

From statement I:
Suman.s rank from the top `to` 3 ranks below Deepak. But there is no information regarding Deepak.s rank. So, statement I is not sufficient.
From statement II :
Deepak.s rank from the bottom `to` 23rd.
So, Deepak.s rank from the top `to` (40 - 23) + 1 or 18th.
But there is no information regarding Suman.s rank. So, statement II is not sufficient.
From statement III :
Suman.s rank from the bottom `to` 3 ranks above Deepak.
But there is no information regarding Deepak.s rank.
From I & II, we get
Suman.s rank from the top `to` (18 + 3) or 21st. So, statements I and II together are sufficient.
From II & III, we get
Suman.s rank from the bottom `to` (23-3) or 20th. So, Sumna.s rank from the top `to` (40 - 20) + 1 or 21st.
So, statements II and III together are sufficient.
Therefore, only statement II and either statement I or III together are necessary to answer the given question.