The average of 8 consecutive even numbers written in ascending order is 17. What is the average of the last three numbers, 36 and 53?
Show answer & explanation
Correct answer: A
Explanation
The correct answer is Option 1 i.e 31.
Let the 8 consecutive even numbers = (2a), (2a + 2), (2a + 4), (2a + 6), (2a +8), (2a + 10), (2a +12), (2a + 14).
Average = Sum of observations/ number of observations
Sum of all 8 consecutive even numbers = Average × Number of observations.
⇒16a + 56 = 17 × 8
⇒16a = 136 - 56
⇒ a = 5
Now the last three numbers = 20 , 22 , 24
Average of last three numbers, 36 and 53 =
⇒ 31.