the mean of a set of thirteen postive integers is 11.when a number k is taken out from the set of the numbers,its mean becomes 11.25.The value of k is.....

the mean of a set of thirteen postive integers is 11.when a number k is taken out from the set of the numbers,its mean becomes 11.25.The value of k is..... a.7 b.8 c.9 d.10 e.11