shubhangi wrote:

its not understandable.. could u please explain wonder_gmat?i am getting 1/6

Let's say:

A = average of all 11 cars

X = 2A..... (given)

We have to find the total of all cars (including X) in order to find the fraction that contributes to X.

Total = X + 11A ..... (we can use 11A here in place of total cost of all cars besides X)

= 2A + 11A

= 13A

Now, we have to find the fraction of the

total cost that is contributed to X.

Fraction = X / Total

= 2A / 13A

= 2/13 ..... (A's cancel out)

Make sense?