The average of 25 results is 18. The average of first twelve of them is 14 and…
2022
The average of 25 results is 18. The average of first twelve of them is 14 and that of last twelve is 17. Find the thirteenth result.
- A.
78
- B.
74
- C.
66
- D.
70
Attempted by 76 students.
Show answer & explanation
Correct answer: A
Total sum = 25 × 18 = 450. First 12 sum = 12 × 14 = 168. Last 12 sum = 12 × 17 = 204. Thirteenth result = 450 - (168 + 204) = 78.