7 numbers are in arithmetic progression. Average of first and last number of this progression is 9. What is the average of these 7 numbers?
Show answer & explanation
Correct answer: D
Explanation
Given:
Number of terms = 7 (in an Arithmetic Progression)
Average of the first and last terms = 9
According to the formula:
Average in an AP = (First term + Last term) / 2
Average = 9