Aptitude - Average - Discussion
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.
In a cricket team, the average age of eleven players in 28 years. What is the age of the captain? | |
I. | The captain is eleven years older than the youngest player. |
II. | The average age of 10 players, other than the captain is 27.3 years. |
III. | Leaving aside the captain and the youngest player, the average ages of three groups of three players each are 25 years, 28 years and 30 years respectively. |
Total age of 11 players = (28 x 11) years = 308 years.
I. C = Y + 11 
C - Y = 11 .... (i)
II. Total age of 10 players (excluding captain) = (27.3 x 10) years = 273 years.
Age of captain = (308 - 273) years = 35 years.
Thus, C = 35. .... (ii)
From (i) and (ii), we get Y = 24
III. Total age of 9 players = [ (25 x 3) + (28 x 3) + (30 x 3)] years = 249 years.
C + Y = (308 - 249) = 59 .... (iii)
From (i) and (iii), we get C = 35.
Thus, II alone gives the answer.
Also, I and III together give the answer.
Correct answer is (C).
Why do we take C = Y+11?
Thus Captain (C) is same with Youngest player (Y) plus 11.
C = Y+11.
In 1 we have equation C - Y = 11 and in 3 equation is C + Y = 59. Solve those two equations so that we can get captain age.
Please explain this in clearly.
The answer should be 2 only.