Aptitude - Average - Discussion

Nice explanation, Thanks @Rohan.

Let the average age of the whole team by x years.

11x - (26 + 29) = 9(x -1).
11x-55=9x-9.
11x - 9x = -9+55.
2x = 46.
x = 23..
So, the average age of the team is 23 years.

Let average age of whole team =x.

Excluding age of 2 members,average age of remaining 9 players is:

(FORMULA--->Average=sum of data/number of items in data)
So, average age of 9 players is one year less than average age of whole team(x).

i.e (x-1)=sum/9
9(x-1)=sum.

We need to find the average age of 11 players.
We know the sum of ages of 9 players(9(x-1)), now add ages of remaining two players i.e 26+29.
Now total average of cricket team will become;
x=(9(x-1)+26+29)/11.
After simplifying this equation we will get x=23.

How 29 came because 26 years old is captain and 3 years old is wicket-keeper.

How did you get 29?

Very helpful, Thanks @Aarzoo.

@ Aditya.

Here, it is mentioned the captain age is 26 and wicket-keeper is older than captain with three years.

It means captain age=23 and wicket-keeper age= captain age+3. i.e 26.

26 is age of captain.

And we are given that wicket keeper is 3 year older than captain so age of wicket keeper is 29 (26+3).

Why 9(x-1) Instead of 9x-1? Please explain.

Captain age is =26,
Wicketkeeper age is 3 years older than captain that is =26+3=29,
Average of whole team=((Y+26+29)/11)=X,
X=average of the whole team,
Y =total age of remaining 9 members.
Total age of the whole team,
=(Y+26+29)=11X ---> Eq1.

2part
Two are excluded.
So remaining people are 9.
Average of remaining is 1 year less than the whole team,
That is =X-1,
Average of 9 members =(X-1)*Y/9,
Total age of 9 members =Y=9*(X-1) ---> Eq2.

Substitute eq2 in eq 1.
26+29+9X-9 = 11X,
46 = 2X,
X = 23.