Advertisements
Advertisements
प्रश्न
If k,(2k - 1) and (2k - 1) are the three successive terms of an AP, find the value of k.
Advertisements
उत्तर
It is given that k,(2k -1)and (2k +1) are the three successive terms of an AP.
∴ (2k-1) - k= (2k+1) - (2k-1)
⇒ k - 1 =2
⇒ k = 3
Hence, the value of k is 3.
APPEARS IN
संबंधित प्रश्न
If Sn1 denotes the sum of first n terms of an A.P., prove that S12 = 3(S8 − S4).
How many terms of the series 54, 51, 48, …. be taken so that their sum is 513 ? Explain the double answer
In an AP given a3 = 15, S10 = 125, find d and a10.
200 logs are stacked in the following manner: 20 logs in the bottom row, 19 in the next row, 18 in the row next to it and so on. In how many rows are the 200 logs placed, and how many logs are in the top row?
A ladder has rungs 25 cm apart. (See figure). The rungs decrease uniformly in length from 45 cm at the bottom to 25 cm at the top. If the top and bottom rungs are 2 `1/2` m apart, what is the length of the wood required for the rungs?
[Hint: number of rungs = `250/25+ 1`]
Find the sum of the first 25 terms of an A.P. whose nth term is given by an = 7 − 3n
The fourth term of an A.P. is 11 and the eighth term exceeds twice the fourth term by 5. Find the A.P. and the sum of first 50 terms.
If 4 times the 4th term of an A.P. is equal to 18 times its 18th term, then find its 22nd term.
In a flower bed, there are 43 rose plants in the first row, 41 in second, 39 in the third, and so on. There are 11 rose plants in the last row. How many rows are there in the flower bed?
Find an AP whose 4th term is 9 and the sum of its 6th and 13th terms is 40.
If the common differences of an A.P. is 3, then a20 − a15 is
In a school, students decided to plant trees in and around the school to reduce air pollution. It was decided that the number of trees, that each section of each class will plant, will be double of the class in which they are studying. If there are 1 to 12 classes in the school and each class has two sections, find how many trees were planted by the students.
If `4/5` , a, 2 are three consecutive terms of an A.P., then find the value of a.
If the sum of P terms of an A.P. is q and the sum of q terms is p, then the sum of p + q terms will be
The first and last term of an A.P. are a and l respectively. If S is the sum of all the terms of the A.P. and the common difference is given by \[\frac{l^2 - a^2}{k - (l + a)}\] , then k =
x is nth term of the given A.P. an = x find x .
The sum of all odd integers between 2 and 100 divisible by 3 is ______.
Find the sum of those integers from 1 to 500 which are multiples of 2 or 5.
[Hint (iii) : These numbers will be : multiples of 2 + multiples of 5 – multiples of 2 as well as of 5]
Which term of the AP: –2, –7, –12,... will be –77? Find the sum of this AP upto the term –77.
The sum of n terms of an A.P. is 3n2. The second term of this A.P. is ______.
