Advertisements
Advertisements
प्रश्न
Choose the correct alternative answer for the following question .
If for any A.P. d = 5 then t18 – t13 = ....
पर्याय
5
20
25
30
Advertisements
उत्तर
It is given that,
d = 5
Now,
\[t_n = a + \left( n - 1 \right)d\]
\[ t_{18} - t_{13} = \left( a + \left( 18 - 1 \right)d \right) - \left( a + \left( 13 - 1 \right)d \right)\]
\[ = \left( a + 17d \right) - \left( a + 12d \right)\]
\[ = 5d\]
\[ = 5\left( 5 \right)\]
\[ = 25\]
APPEARS IN
संबंधित प्रश्न
Find the sum of all numbers from 50 to 350 which are divisible by 6. Hence find the 15th term of that A.P.
The sum of n, 2n, 3n terms of an A.P. are S1 , S2 , S3 respectively. Prove that S3 = 3(S2 – S1 )
The sum of n terms of three arithmetical progression are S1 , S2 and S3 . The first term of each is unity and the common differences are 1, 2 and 3 respectively. Prove that S1 + S3 = 2S2
Determine the A.P. whose 3rd term is 16 and the 7th term exceeds the 5th term by 12.
How many terms of the AP. 9, 17, 25 … must be taken to give a sum of 636?
Show that a1, a2,..., an... form an AP where an is defined as below:
an = 3 + 4n
Also, find the sum of the first 15 terms.
Find the sum of first 8 multiples of 3.
In an A.P., the sum of first n terms is `(3n^2)/2 + 13/2 n`. Find its 25th term.
The 8th term of an AP is zero. Prove that its 38th term is triple its 18th term.
Find the first term and common difference for the A.P.
`1/4,3/4,5/4,7/4,...`
If Sn denote the sum of n terms of an A.P. with first term a and common difference dsuch that \[\frac{Sx}{Skx}\] is independent of x, then
x is nth term of the given A.P. an = x find x .
Find the value of x, when in the A.P. given below 2 + 6 + 10 + ... + x = 1800.
The sum of the first 15 multiples of 8 is ______.
First four terms of the sequence an = 2n + 3 are ______.
The sum of first 16 terms of the AP: 10, 6, 2, ... is ______.
The sum of first five multiples of 3 is ______.
The nth term of an Arithmetic Progression (A.P.) is given by the relation Tn = 6(7 – n)..
Find:
- its first term and common difference
- sum of its first 25 terms
