The average mark obtained by 23 candidates in an examination is 45. The average of the first ten is 55 while the last eleven is 40 .The marks obtained by the 11th candidate is ?
Options:
(A) 26
(B) 45
(C) 90
(D) 80
(E) 65 Now, let's think a bit. Some random thoughts:
It is clear that 23 x 45 = 10 x 55 + K + 11 x 40 K = 45
The final answer: (B).