The average of 21 results is 20. Average of 1st 10 of them is 24 that of last 10 is 14. the result of 11’th is :
(A) 42
(B) 44
(C) 46
(D) 40
Answer: (D)
Explanation:
11'th result = sum of 21 results – sum of 20 results = 21 x 20 – (24 x 10 + 14 x 10) = 420 – (240 + 140) = 420- 380 = 40