Question

If 6th term of a G.P. is 46875 and its 4th term is 375. Find its 9th term.

Answer 1

we know nth term of an AP is
tn=a+(n-1) d
where a is first term and d is common difference .
now ,
46875=a+(6-1) d
46875=a + 5d -------------------(1)


again
375 =a+(4-1) d
375 =a +3d -------------------(2)
now solve equation (1) and (2)
then
d=23250
a=-69375
now ,
9th term of AP=-69375 +8 (23250)
=-69375 +186000
=116625