# Aptitude | Progressions | Question 6

Find Arithmetic Mean of series: 2, 2.5, 3, 3. 5, 4, 4. 5……….11**(A)** 13/2**(B)** 25/8**(C)** 19**(D)** 22/9**Answer:** **(A)****Explanation:**

Arithmetic mean AM of the series is given by = (a1+a2+a3+…..+an)/n ……… (1)

But the given series is also an AP which sum is given by = (n/2)*(a1+an) ………..(2)

From equation (1),(2) we get,

AM=(a1+an)/2

AM=(2+11)/2=13/2