Aptitude - Average - Discussion

Let the Avg. Age = X.
=> 11x-(26+29) = 9(x-1).

=> 11x-55 = 9x-9.
=> 11x-9x = 55-9.

=> 2x = 46.
=> x = 46/2 = 23yrs. answer.

Let the average age whole team i.e.
avg = w/11.
w = 11 avg.

If two persons are excluded in the team then the avg is less than 1 of original avg. Therefore,

avg-1 = w-26-29/9.
9avg-9 = 11avg -55 .
2avg = 46.
avg = 23.

Average age of whole team is 23 years.

Here the average of 11 members = x.

If two are excluded then average of 9 members is 1 year less than the average of the whole team so = 9(x-1).

How did you get 9(x-1)? Please explain me.

@Angana,

Let x=age.

11x is the age of all 11 members. but since the captain and wicket keepers age is given, equation will be:
11x-(26+(26+3))
=11x-55.

Now out off 11 members, we are given the ages of 2 members. so v have to find the age of 9 members.the age of 9 members, according to the question is one year less than the average age of the whole team. that is x-1. so equation will be:
9(x-1)
=9x-9.

Putting both equations together,

11x-55 = 9x-9
11x-9x = 55-9
2x = 46.
x = 23.

"11x - (26 + 29) = 9x - 9" how this 9x - 9 came from? please explain. I don't understand.

In question its given 3 years older. It should be clearly given like 3 years older than captain.

Sir you are saying that the wicket keeper's age was 29 but in the problem it was not mentioned then how can one take it as 29 years as the age of wicket keeper?

1. The captain of a cricket team of 11 members is 26 years old and the wicket keeper is 3 years older

Step1. Let Avg age of whole team be x except the captain and wicketkeeper.

we can write as eq: (X+26+29)/11

Step2.If the ages of these two are excluded, the average age of the remaining players is one year less than the average age of the whole team

Means x/9=((X+26+29)/11)-1
(x/9)+1=(x+55)/11
11x+99=9x+495
2x=396
x=198
Avg. age of whole team be x+55/11=253/11=23

Whole team = X.

11X-55=99-9.

2X=64.

X=23.