Profit and Loss - General Aptitude

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.
Q1:

By selling an article what is the profit percent gained?
I.  5% discount is given on list price.
II.  If discount is not given, 20% profit is gained.
 III.  The cost price of the articles is Rs. 5000.

A Only I and II

B Only II and III

C Only I and III

D All I, II and III

E None of these

ANS:A - Only I and II

 I. Let the list price be Rs. x.

Then, S.P. = 95% of Rs. x = Rs. x x 95 = Rs. 19x
100 20
II. When S.P. = Rs. x and gain = 20%.
Then, C.P. = Rs. 100 x = Rs. 5x
120 6
 Gain = 19x - 5x = 57x - 50x = 7x
20 6 60 60
 Gain % = 7x x 6 x 100 % = 14%.
60 5x
Thus, I and II only give the answer.  Correct answer is (A).