In an increasing geometric series, the sum of the second and the sixth term is 25/2 and the product of the third and fifth term is 25. Then, the sum…

Question

In an increasing geometric series, the sum of the second and the sixth term is 25/2 and the product of the third and fifth term is 25. Then, the sum of 4^th,6^th and 8^th terms is equal to:

MARKS Content Team · Accepted Answer

Correct answer: (A) 35. a, ar, ar^2.... T_2+T_6=25/2⇒ar1+r^4=25/2 a^2r^21+r4^2=625/4 ⋯1 T_3·T_5=25⇒ar^2ar^4=25 a^2r^6=25 ...2 On dividing 1 by 2 1+r4^2r^4=25/4 4r^8-17r^4+4=0 4r^4-1r^4-4=0 r^4=1/4,4⇒r^4=4 (an increasing geometric series) a^2r^6=25⇒ar3^2=25 T_4+T_6+T_8=ar^3+ar^5+ar^7 =ar^31+r^2+r^4 =51+2+4=35

In an increasing geometric series, the sum of the second and the sixth term is $\frac{25}{2}$ and the product of the third and fifth term is $25 .$ Then, the sum of $4^{t h}, 6^{t h}$ and $8^{t h}$ terms is equal to:

Solution

Relevant Questions

In an increasing geometric series, the sum of the second and the sixth term is 252 and the product of the third and fifth term is 25. Then, the sum of 4th,6th and 8th terms is equal to:

Solution

Relevant Questions

In an increasing geometric series, the sum of the second and the sixth term is $\frac{25}{2}$ and the product of the third and fifth term is $25 .$ Then, the sum of $4^{t h}, 6^{t h}$ and $8^{t h}$ terms is equal to: