Question

Find the common difference of an



a.P whose first sum is 1 and the sum of first 4 terms is one-third of the sum of its next four terms

Answer 1

Answer:

Step-by-step explanation:

let d is common difference of AP

now first 4term is 5,5+d,5+2d,5+3d

and next 4term 5+4d,5+5d,5+6d,5+7d

now according to question  

20+6d=(20+22d)/2

20+6d=10+11d

d=2