Question
Download Solution PDFFind the sum of the first 153 terms of an AP whose first term and third term are 170 and 180 respectively.
Answer (Detailed Solution Below)
Detailed Solution
Download Solution PDFGiven:
First term (a) = 170
Third term = 180
Number of terms (n) = 153
Formula used:
Sum of n terms (Sn) = n/2 × [2a + (n - 1)d]
Common difference (d) = (Third term - First term)/2
Calculation:
d = (180 - 170)/2
⇒ d = 10/2
⇒ d = 5
S153 = 153/2 × [2 × 170 + (153 - 1) × 5]
⇒ S153 = 153/2 × [340 + 152 × 5]
⇒ S153 = 153/2 × [340 + 760]
⇒ S153 = 153/2 × 1100
⇒ S153 = 153 × 550
⇒ S153 = 84150
∴ The correct answer is option (1).
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.