SOLUTION: In a geometric progression of positive terms, the 5th term is 9 times the 3rd term and the sum of the 6th and 7th terms is 972. Find the
a) common ratio
b) sum of the first 6 te
Algebra.Com
Question 880917: In a geometric progression of positive terms, the 5th term is 9 times the 3rd term and the sum of the 6th and 7th terms is 972. Find the
a) common ratio
b) sum of the first 6 terms
Answer by richwmiller(17219) (Show Source): You can put this solution on YOUR website!
a)
common ratio r=3
b)
Tn = T1 * r^(n - 1)
T7 = T1 * 3^(6)
T6 = T1 * 3^(5)
T7 +T6 =972
T1 * 3^(5)+ t * 3^(6)=972
T1*(3^5+3^6)=972
T1*243+729=972
T1*972=972
T1=1
S=T1*(1 - r^n)/(1 - r)
S=1*(1 - 3^6)/(1 - 3)
S=(1 - 3^6)/(1 - 3)
S=(1-729)/-2
S=-728/-2
S=364
RELATED QUESTIONS
the 5th term in a geometric progression is 9 times the 3rd term and the sum of the 6th... (answered by Boreal,ikleyn)
In a geometric progression the 5th term is 9 times the 3rd term and the sum of the 6th... (answered by htmentor)
the 3rd and 6th term of a geometric progression are 48 and 14 2/9 respectively. Write... (answered by Edwin McCravy)
For a geometric sequence, the sum of the 4th and 5th terms is 144. The sum of the 2nd and (answered by richwmiller)
In a geometric progression, the 2nd term is 8 and the 7th term is .25. Find the sum of... (answered by josgarithmetic)
In a geometric progression,the 6th term is 96 and the common ratio is -2. Find the sum of (answered by ikleyn)
Please help me solve this question: In the gp, the sum of the 2nd and 3rd terms is 9. The (answered by Theo)
The 5th term of a geometric progression is 4375 and it 2nd term is 35.find the 3rd... (answered by josgarithmetic)
In a geometric progression the sum of 2nd and 4th terms is 30. The difference of
6th... (answered by richwmiller)