If first 6 results average is 49 & last 6 result average is 52
The average of 11 results is 50. If first 6 results average is 49 & last 6 result average is 52, then find the 6th
(a) 49
(b) 56
(c) 50
(d) 312
Answer: (b) 56
Solution:-
Average of 11 results = 50
so total sum of 11 numbers = 550
Let 6th number is X,
So, according to the given condition
sum of first 5 numbers = 49 x 6 – x = 294 – X
sum of last 5 numbers = 52 x6 – x = 312 – X
so 6th number x = 550 – (294 – X) – (312 – X) = 2 X- 56
so X = 2 X- 56 implies X = 56
Hence, the correct answer is option (b) 56.