Question

The 11 th term and 29 th term of an AP. are in the ratio 3: 8. What is the ratio of sum of first 13 terms and first 17 terms of the AP

Answer 1

th term of an AP is a+(n-1)d
where a is first term ,n are no. of terms and d is the common differnce

Answer 2

a+10d/a+28d=3/8

Answer 3

8a+80d =3a+84d
5a=4d
a=4/5d

Answer 4

sum of first 13 terms and first 17 terms of the AP..
can be written as
{13/2[2a+12d]}/{17/2[2a+16d]}
here , i have to put a value

Answer 5

tell me i have done correct or not

Answer 6

some budy plse tell me if i have done right or wrong