Bissoy.com
Doctors Medicines MCQs Q&A

The sum of fourth and twelfth term of an arithmetic progression is 20. What is the sum of the first fifteen terms of that arithmetic progression?

The sum of fourth and twelfth term of an arithmetic progression is 20. What is the sum of the first fifteen terms of that arithmetic progression? Correct Answer 150

ধরি, ধারাটির ১ম পদ a এবং সাধারণ অন্তর d a + 3d + a + 11d = 20 2a + 14d = 20 S15 = 15/2 { 2a + ( 15 - 1) d } = 15/2 × ( 2a + 14d) = 15/2 × 20 = 150

Related Questions

The following question has three statements. Study the question and the statements and decide which of the statement (s) is/are necessary to answer the question. What is the first term of the arithmetic progression? I) The difference between the 16th term and 9th term of an arithmetic progression is 49. II) The average of 12 terms of an arithmetic progression is 40.5. III) The common difference is 5 more than the first term of the arithmetic progression.
The sum of the fourth and twelfth term of an arithmetic progression is 20. what is the sum of the first 15 terms of the artihmetic progression?
In the following question, two statements are numbered as A and B. On solving these statements, we get quantities A and B respectively. Solve both quantities and choose the correct option. Quantity I: A sum of 45 terms of an Arithmetic progression is 5400. The ratio between the 11th term and 51st term is 3 : 13. Find the difference between the first term of progression and the common difference between the terms of progression. Quantity II: What should come to the place of ‘?’ in the following question: 234 + 35% of 920 – 4 / 5th of 110 = 7 / 9th of 378 + ? × 87
In an arithmetic progression (AP), the 9th term is 5 times the 2nd term and the 8th term is 1 more than 10 times the first term. What is the 4th term of the geometric progression (GP) whose first term is the second term of AP and whose common ratio is equal to the common difference of AP?
The sum to infinity of a geometric progression is 39/2. The sum to infinity to squares of the terms of the geometric progression is 253.5. What is the sum to infinity of cubes of the terms of the geometric progression?
What is the average of the first sixty terms of an arithmetic progression having the first term of progression is 20 and the difference in terms T18 and T7 is 44?
An arithmetic progressions in which first term is 4. Also, the sum of the first ten terms is 25/56 times of the sum of the first sixteen terms. Then, find the sum of the first 52 terms?
The sum of the first 10 terms of a GP is equal to the sum of the first 12 terms in the same GP. The sum of the first 17 terms is 42, what is the fourth term in the GP?
Humans and robots can both perform a job but at different efficiencies. Fifteen humans and five robots working together take thirty days to finish the job, whereas five humans and fifteen robots working together take sixty days to finish it. How many days will fifteen humans working together (without any robot) take to finish it?
If the position of the fifth and twelfth letters of the word ‘GLORIFICATIONS’ is interchanged and likewise the positions of the fourth and fourteenth letters, the third and tenth letter, the second and eleventh letters and the first and thirteenth letters are interchanged, which of the following will be the twelfth letter from the right end?