Find the sum of the G.P.:

1/5, 1/25, 1/125, 1/625, … to n terms.

This question was previously asked in
UP Police SI (दरोगा) Official PYP (Held On: 29 Nov 2021 Shift 1)
View all UP Police Sub Inspector Papers >
  1. 3/4(1- (1/5n)) 
  2. 1/4(1- (1/5n))
  3. (1- (1/5n))
  4. 4/5((1- 1/5n))

Answer (Detailed Solution Below)

Option 2 : 1/4(1- (1/5n))
Free
UP Police SI (दरोगा) Official PYP (Held On: 2 Dec 2021 Shift 1)
47.2 K Users
160 Questions 400 Marks 120 Mins

Detailed Solution

Download Solution PDF

Given:

First term (a) = 1/5

Common ratio (r) = 1/25 ÷ 1/5 = 1/5

Number of terms (n) = n

Formula Used:

Sum of n terms of a G.P. = Sn = a × (1 - rn) / (1 - r), where |r| < 1

Calculation:

Substitute the values:

⇒ Sn = (1/5) × (1 - (1/5)n) / (1 - 1/5)

⇒ Sn = (1/5) × (1 - (1/5)n) / (4/5)

⇒ Sn = (1 - (1/5)n) / 4

⇒ Sn = 1/4 × (1 - (1/5)n)

Final Answer:

The sum of the given G.P. up to n terms is: 1/4(1 - (1/5)n).

Latest UP Police Sub Inspector Updates

Last updated on Jul 4, 2025

-> The UP Police Sub Inspector 2025 Notification will be released by the end of July 2025 for 4543 vacancies.

-> A total of 35 Lakh applications are expected this year for the UP Police vacancies..

-> The recruitment is also ongoing for 268  vacancies of Sub Inspector (Confidential) under the 2023-24 cycle.

-> The pay Scale for the post ranges from Pay Band 9300 - 34800.

-> Graduates between 21 to 28 years of age are eligible for this post. The selection process includes a written exam, document verification & Physical Standards Test, and computer typing test & stenography test.

-> Assam Police Constable Admit Card 2025 has been released.

Get Free Access Now
Hot Links: teen patti gold apk teen patti master downloadable content teen patti apk download teen patti bindaas teen patti rummy