series sequence qns (2) (1 Viewer)

[bos1234]

Find the approximate value of:

55[1 + (1.035) + (1.035)^2 + ...] to 12 terms

a = 1 , r = 1.035 , n = 12

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

=1-1.035^12/(1-1.035) x 55
=803....

but answer is 867 3/7

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similar qn
55[1+ (1.035)^-1 + (1.035)^-2 + ...] to 12 terms

a = 1
n=12
r = 1/1.035

i get 550....
answer 565

thanks bye

 

[watatank]

S_n = a(rⁿ- 1)/[r-1] is the correct formula, there is no rⁿ in the denominator and also r > | 1 | so you take 1 from r and rⁿ respectively.

 

[z600]

Your formula is wrong

 

[z600]

Well, i got the same answer as you did. Maybe the answer is wrong?? What book is this out of?

I did it without the formula, so its either the answer is wrong or we interpret the question wrong.

 

[bos1234]

that was accident. still getting some wrong answer. Some1 please try

 

[blakwidow]

Your answers seem to be right. Prolly the book is wrong