# Aptitude - Average - Discussion

### Discussion :: Average - Data Sufficiency 2 (Q.No.1)

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.

 How many marks did Tarun secure in English? I. The average mark obtained by Tarun in four subjects including English is 60. II. The total marks obtained by him in English and Mathematics together are 170. III. The total marks obtained by him in Mathematics and Science together are 180.

 [A]. I and II only [B]. II and III only [C]. I and III only [D]. All I, II and III [E]. None of these

Explanation:

I gives, total marks in 4 subjects = (60 x 4) = 240.

II gives, E + M = 170

III gives, M + S = 180.

Thus, none of (A), (B), (C), (D) is true. Correct answer is (E).

 Lakshmi S S said: (Dec 14, 2011) Can any one tell me then what is required to solve this type of issues ?

 Shobhit Dube said: (Oct 15, 2012) We know 4 subject their. we know three subject name math,science,english. i let 4th subject x. then e+M+S+X=240 ---------1 m+S=180-----------------2 put this in 1 eq. e+x+180=240 e+x=60 x=e-60 this put in eq.1 and also put m+s=180 e+180+e-60=240 2e+120=240 2e=120 e=60 ans

 Manish said: (Dec 12, 2012) @Shobhit Dube. There are 4 Sub. and as per your sol; it shows E=60 and M+S=180 hence Sum will be 240. (240= 4 Sub). In such a case where is the marks of 4th sub.

 Shaby said: (Jan 9, 2014) @Manish - I agree with you. @Shohit Dube - your solution is wrong.

 Bharat said: (Oct 17, 2014) @Shohit Dube - your solution is wrong. Because at least 2 equations needed to solve 2 variables. {n - number of variables - then n equations needed for solving it }. You can't use same equation for putting the value of x from which you have derived value of x.

 Bhushi said: (Apr 18, 2015) What about one subject is having 0 marks?

 Kanna said: (Jan 31, 2016) @Sohibit Dube. Your solution is totally wrong as if x+e = 60 then e = 60-x not e-60.

 Meet Shah said: (Aug 1, 2016) Why 1 and 2 not an answer here it's only saying about English then why is it so?

 Anant said: (Jun 16, 2017) We can obtain marks in English by this, Marks in 4 subjects. (E+M+S+X)/4=60. E+M+S+X=240. And E+M=170 ---eqn1. M+S=180----eqn2. eqn2-eqn1 we get; S-E=10, S=10+E. now substitute in here E+(10+E)+170=240. 2E=60, E=30.

 Bala said: (Jul 25, 2017) @Anant. So the answer is all three?

 Ankur said: (Feb 9, 2018) @Anant. According to the question he got 60% (avg. Of 4 sujects). It means each subject carrying 100 marks but as per your solution, he got 150 marks in maths.

 Ankur said: (Feb 9, 2018) Also M+E= 180 so M is 150. But S+M= 170 S= 40 Here M= 130.

 Bhavya said: (Mar 13, 2018) Answer should be the option : D, right.

 Susmitha said: (Jul 19, 2019) @All. Here, They are just asking English marks. While 1 and 2 are definitely giving the marks of English. My answer is both 1 and 2 are right. Those statements give marks of English clearly.