How many terms are there in the GP 5, 20, 80, 320........... 20480?
A. 5
B. 6
C. 8
D. 9
E. 7
Answer: Option E
Solution(By Examveda Team)
Common ratio, r = $$\frac{{20}}{5}$$ = 4 Last term or nth term of GP = arn - 1 20480 = 5 × (4n - 1) Or, 4n - 1 = $$\frac{{20480}}{5}$$ = 46 So, comparing the power, Thus, n - 1 = 6 Or, n = 7 Number of terms = 7This Question Belongs to Arithmetic Ability >> Progressions
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Find the first term of an AP whose 8th and 12th terms are respectively 39 and 59.
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The sum of the first 16 terms of an AP whose first term and third term are 5 and 15 respectively is
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Plz brothers n-1=6
Yes answer is 7
Bcoz 20480/5=4096=4 to the power 6 not 8
n-1=6
n=7
4 to the power 6 = 4096
Take 4^6 and then solve
20480 devide by 5 then we get 4096 if we multiple 4 by 6 times then we get the correct answer and answer is 7 how
4^6=4096
4^6=4^(n-1)
n-1=6
N=7