Question

there are n arthmatic mean between 8and 17. the ratio of the last mean to the first mean 3:1 find the value of n​

Answer 1

Answer:

3,a1,a2,....an,17ϵA.P.(n+2 terms)

⇒3,3+d,a2,a2.....17−d,17ϵA.P.

⇒3+d17−d=13

∴17−d=9+3d⇒d=2

Now a+(n+1)d=tn+2=17

⇒3+(n+1)(2)=17⇒n=6