Aptitude - Average - Discussion

Discussion Forum : Average - Data Sufficiency 2 (Q.No. 1)
Directions to Solve

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.

I and II only
II and III only
I and III only
All I, II and III
None of these
Answer: Option
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).

Discussion:
17 comments Page 2 of 2.

Kanna said:   10 years ago
@Sohibit Dube.

Your solution is totally wrong as if x+e = 60 then e = 60-x not e-60.

Bhushi said:   1 decade ago
What about one subject is having 0 marks?

Bharat said:   1 decade ago
@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.

Shaby said:   1 decade ago
@Manish - I agree with you.
@Shohit Dube - your solution is wrong.

Manish said:   1 decade ago
@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.

Shobhit dube said:   1 decade ago
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
(1)

Lakshmi S S said:   1 decade ago
Can any one tell me then what is required to solve this type of issues ?


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