Aptitude - Average - Discussion

11x - (26 + 29) = 9(x -1) can you explain that how it comes?

Let Avg age of dull team be x
so acc to formula sum/n=avg----equation 1)

we have 26+29+ 9 members of cricket team / 11 = x --- equation 2)

Now Acc to ques: the average age of the remaining players is one year less than the average age of the whole team if those two players are excluded so again putting in eq 1

9 members / 9 = x- 1 ---- equation 3

where x is avg of whole team

get the value of 9 members from equation 2 and place it in eq 3
we will get the ans as 23

Thanks for the detailed explanation. Now I got it!.

Explanation:
Let x be the total ages of everyone in the team except the captain and wicketkeeper:
x / 9 = Avg. age of everyone except capt. and wkt keeper
(x + 26 + 29) / 11 = (x + 55) / 11 = Avg. age of full team
So:
(x + 55)/11 = (x/9) + 1 (since the average for team without those two is one less than the average with those two)
Add that 1 and you get (x+9)/9 and then cross multiply to get:
11x + 99 = 9x + 495
x = 198
So average age of team:
198 + 55 = 253
253/11 = 23 years

Much longer than explanation given above but it explains things better.

Let the average age of 9 members be x.

(x+55)/11 - x/9 = 1

=> x=198.

(198+55)/11 => 23.

No Ratnakar. You are wrong.

Why 9(x-1), it may be 9x-1.

Please explain in detail.

11x - (26 + 29) = 9x - 9
11x - 9x = -9 + (26 + 29)
11x - 9x = 46

Can you explain how that 46 comes?