Average of first ‘N’ multiples of 3 is 66. What is the value of ‘N’?
Show answer & explanation
Correct answer: D
Explanation
Given:
Average of the first N multiples of 3 = 66
According to the formula:
Average = (First term + Last term) / 2
Series: 3, 6, 9, …, 3N
Average = (3 + 3N) / 2 = 66
3 + 3N = 132
3N = 129
N = 43