Question

Find the common difference of an A.P. whose first term is 5
and the sum of the first four terms is half the sum of the next
four terms.
answer​

Answer 1

Answer:

2

Step-by-step explanation:

Let d is common difference of AP

Now first 4 terms are 5, 5+d, 5+2d, 5+3d

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

Given that, the sum of its first four terms is half the sum of the next four terms.

i.e.,

5 + 5+d + 5+2d + 5+3d=25+4d + 5+5d + 5+6d + 5+7d

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

20+6d=10+11d

d=2

Hence,  the  common  difference  of  the  given  A.P.  is   2