Question

12. The first term of a G.P. is 5 and the last term is 1280. If the sum of all terms is 2555 , find the number of terms. 13 The sum of the first four terms of a G.P. is five times the sum of the first two terms. Find the value of the common ratio, \( r \), given that \( r>1 \).

          12. The first term of a G.P. is 5 and the last term is 1280. If the sum of all terms is 2555 , find the number of terms.
13 The sum of the first four terms of a G.P. is five times the sum of the first two terms. Find the value of the common ratio, \( r \), given that \( r>1 \).

12. The first term of a G.P. is 5 and the last term is 1280. If the sum of all terms is 2555 , find the number of terms.
13 The sum of the first four terms of a G.P. is five times the sum of the first two terms. Find the value of the common ratio, r, given that r>1.

Added by Jennifer V.

Mathematics for IIT JEE Main and Advanced Differential Calculus Algebra Trigonometry

Sanjiva Dayal IIT Kanpur 1st Edition

Chapter 9

Instant Answer

Solved by Expert Madhur L

09/20/2023

Step 1

Step 1: Identify the given information for question 12: - First term (\(a\)) = 5 - Last term (\(l\)) = 1280 - Sum of all terms (\(S_n\)) = 2555 Show more…

Show all steps

Thanks for your feedback!

12. The first term of a G.P. is 5 and the last term is 1280. If the sum of all terms is 2555 , find the number of terms. 13 The sum of the first four terms of a G.P. is five times the sum of the first two terms. Find the value of the common ratio, \( r \), given that \( r>1 \).