The average of 25 results is 50. The average of first 12 of those is 14 and the average of last 12 is 17. What is the 13th result?  Choose the correct choice from the following answers:
A) 741
B) 752
C) 878
D) 785
E) 458
Solution: Sum of 1st 12 results = 12*14   Sum of last 12 results = 12*17   13th result = x (let)   Now,   12*14+12*17+x = 25*50   Or, x = 878.   Answer: Option 878
<result>C</result>
The average of 25 results is 50. The average of first 12 of those is 14 and the average of last 12 is 17. What is the 13th result?