Advertisements
Advertisements
प्रश्न
Fill up the boxes and find out the number of terms in the A.P.
1,3,5,....,149 .
Here a = 1 , d =b`[ ], t_n = 149`
tn = a + (n-1) d
∴ 149 =`[ ] ∴149 = 2n - [ ]`
∴ n =`[ ]`
Advertisements
उत्तर
In the A.P. 1,3,5,....,149
a = 1 , d = 2 , tn = 149
tn = a + (n-1)d
149 = 1+ (n-1) × 2
149 = 1 + 2n -2
149 = 2n - 1
∴ 2n = 150
∴ n = 75
APPEARS IN
संबंधित प्रश्न
Find the sum given below:
34 + 32 + 30 + ... + 10
In an AP given an = 4, d = 2, Sn = −14, find n and a.
A spiral is made up of successive semicircles, with centres alternately at A and B, starting with centre at A of radii 0.5, 1.0 cm, 1.5 cm, 2.0 cm, .... as shown in figure. What is the total length of such a spiral made up of thirteen consecutive semicircles? (Take `pi = 22/7`)
[Hint: Length of successive semicircles is l1, l2, l3, l4, ... with centres at A, B, A, B, ... respectively.]
In an A.P., if the first term is 22, the common difference is −4 and the sum to n terms is 64, find n.
The first term of an A.P. is 5, the last term is 45 and the sum of its terms is 1000. Find the number of terms and the common difference of the A.P.
Write an A.P. whose first term is a and common difference is d in the following.
a = –3, d = 0
Find the first term and common difference for the A.P.
127, 135, 143, 151,...
In an A.P. 17th term is 7 more than its 10th term. Find the common difference.
The 9th term of an A.P. is equal to 6 times its second term. If its 5th term is 22, find the A.P.
The sum of the first 7 terms of an A.P. is 63 and the sum of its next 7 terms is 161. Find the 28th term of this A.P.
If Sn denotes the sum of first n terms of an A.P., prove that S12 = 3(S8 − S4).
The nth term of an A.P., the sum of whose n terms is Sn, is
The common difference of the A.P. \[\frac{1}{2b}, \frac{1 - 6b}{2b}, \frac{1 - 12b}{2b}, . . .\] is
Q.1
Find t21, if S41 = 4510 in an A.P.
If the sum of three numbers in an A.P. is 9 and their product is 24, then numbers are ______.
Find the sum of those integers from 1 to 500 which are multiples of 2 as well as of 5.
Solve the equation:
– 4 + (–1) + 2 + 5 + ... + x = 437
Three numbers in A.P. have the sum of 30. What is its middle term?
The sum of 40 terms of the A.P. 7 + 10 + 13 + 16 + .......... is ______.
