Question

find the mean of all even numbers from 1 to 25

Answer 1

Step-by-step explanation:

Required sum = 2+4+6+8….24. These numbers form an Arithmetic progression with the first term ,a= 2 and common difference, d= 4–2 = 2 and last term,l = 24

The nth term of an AP = a+ (n-1)d .

From this , 24 = 2 + (n-1) 2 which implies 22/2 = (n-1) which implies 12= n .This means 24 is the 12th term of this AP or in other words there are 12 terms in this AP.