Question

Find the sum of the series 2 + 6 + 18 + 54 + ...... + 4374.​

Answer 1

as we know,

tn = 2a + (n-1) d

it will definitely help u...

Answer 2

Heya !!

Here's your answer !!

Given series is 2+6+18+54+.......+4374.

Clearly, the ratio of any term by its preceding term is same.

So, the above series froms GP with the first term, a = 2,

Common ratio, r = 6/2 = 3 > 1

and last term, l = 4374.

therefore,

Required sum = ( lr - a) /( r - 1)

= ( 4374 × 3 - 2)/(3 - 1)

= 13120/2

= 6560.

Hence, the sum of the qiven series is 6560.

glad help you,

it helps you,

thanks.