Question

Write the first term of an arithmetic sequence, whose first term is 30 and the sum of first 5 term is 300

Answer 1

Answer:

The quest is trivial. Since it is already given, term is 30 and it is asked to find the first term which is obviously 30. I think the question is to find the common difference.

In that case, the process is as follows.

Step-by-step explanation:

first term = a = 30

let common difference = d

sum of first 5 term =

S5 = (5/2){2×30+(5-1)×d} = 300

=> 60+4d = 300×2/5 = 120

=> 4d = 120-60 = 60

=> d = 60/4 = 15