Question

Q 50 Find the sum of 10 terms of a G.P. with first term and common ratio of 8 and 3 respectively.
Ops: A.
B.
c.
236192
219631
263291
D.
236294​

Answer 1

Answer:

We have a=8, r=3, n=10

Sn=a(r^n-1)/r-1

S10= 8(3^10-1)/3-1

=8(59049-1)/2

=4(59048)

=236192

So correct answer is option A

Answer 2

The answer is option (A) 236192

Given:

First term of GP, a = 8

Common ratio, r = 3

To find:

Sum of 10 terms in given GP  

Solution:  

As we know sum of n terms in GP,  S$_{n}$ = a[(rⁿ-1)/(r-1)]  

where a = first term and r = common ratio

From given data a = 8, r = 3 and number of terms n = 10

⇒ Sum of 10 terms, S₁₀ = a[(rⁿ-1)/(r-1)]  

= 8 [(3¹⁰-1) / (3 - 1)]  

= 8 [ (59049 - 1)/ 3 - 1 ]

= 8 [ 59048 / 2 ] = 8 [ 29,524 ] = 236192

Therefore, sum of 10 terms = 236192  

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