Multiple choice

The average of the even numbers from 1 to 30 is.

  1. $15$
  2. $19$
  3. $17$
  4. $16$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Even numbers from 1 to 30 are: 2, 4, 6, ..., 30. There are 15 even numbers. Sum = (n/2)(first + last) = 15/2 × (2+30) = 15 × 16 = 240. Average = Sum/n = 240/15 = 16. Alternatively, average of an arithmetic progression equals (first + last)/2 = (2+30)/2 = 16.