Question

Write the first five terms of the geometri.c sequence in which a1 - 8 and the common ratio is 5/2.

Answer 1

D right on edg 2020

Explanation:

Answer 2

8 , 20, 50, 125, 625/2 option D

Explanation:

Given that,

first term a₁ = 8

common ratio (r) =
`(5)/(2)`

We need to find the five terms of the geometric progression

We know that the nth term formula :

aₙ = a₁rⁿ-¹

where a₁ is first term and r is the common ratio

n is the number of terms

Second term (n=2)

a₂ = 8*
`((5)/(2) )^(2-1)` =
`(8*5)/(2)` = 20

Third term (n = 3)

a₃ = 8*
`((5)/(2) )^(3-1) = 8*((5)/(2) )^(2)  = ((8*25)/(4) ) = 50`

Forth term (n=4)

a₄ =
`8((5)/(2) )^(4-1) = 8*((5)/(2) )^(3)  = ((8*125)/(8) ) = 125`

Fifth term (n=5)

a₅ =
`8((5)/(2) )^(5-1) = 8*((5)/(2) )^(4)  = ((8*625)/(16) ) = (625)/(2)`

So, five terms are :

8 , 20, 50, 125, 625/2