KnowledgeBoat Logo

Mathematics

In a G.P., the third term is 24 and 6th term is 192. Find the 10th term.

AP GP

30 Likes

Answer

Given, a3 = 24, a6 = 192.

By formula, an = arn - 1.

⇒ a3 = ar(3 - 1)
⇒ ar2 = 24.             (Eq 1)

⇒ a6 = ar(6 - 1)
⇒ ar5 = 192.            (Eq 2)

Dividing Eq 2 by Eq 1

ar5ar2=19224r3=8r3=(2)3r=2\Rightarrow \dfrac{ar^5}{ar^2} = \dfrac{192}{24} \\[1em] \Rightarrow r^3 = 8 \\[1em] \Rightarrow r^3 = (2)^3 \\[1em] \Rightarrow r = 2

Putting value of r in Eq 1,

a(2)2=244a=24a=610th term of G.P.=a10a10=6(2)101=6(2)9=6×512=3072.\Rightarrow a(2)^2 = 24 \\[1em] \Rightarrow 4a = 24 \\[1em] \Rightarrow a = 6 \\[1em] \text{10th term of G.P.} = a{10} \\[1em] \Rightarrow a{10} = 6(2)^{10 - 1} \\[1em] = 6(2)^9 = 6 \times 512 = 3072.

Hence, the 10th term of the G.P. is 3072.

Answered By

15 Likes


Related Questions