Question

in a gp t2 =24,t5=81 then find a​

Answer 1

a = 16

Explanation:

Equation of nth term in GP:

Tn = (a*r)^(n-1)

t2 = 24 that means a*r = 24

t5 = 81 that means a*(r)^4 = 81

t5/t2 => 81/24

That means (r)^3 = 81/24

Therefore r = 3/2

Substituting value of r in t2 we get,

a*(3/2) = 24

Therefore a = 24*(2/3)

Hence a = 16

Answer 2

Answer:

a=16

Step-by-step explanation:

the fifth term of a g.p. is 81 ---> ar^4 = 81

second term is 24 -----> ar = 24

divide them:

(ar^4)/(ar) = 81/24

r^3 = 27/8

r = 3/2

then in ar=24

(3/2)a = 24

a = 16