Advertisements
Advertisements
Question
Find the 23rd term of the following A.P.: 9, 4,-1,-6,-11.
Advertisements
Solution
9, 4,-1,-6,-11
a = 9 , d = 4 - 9 = -5 , n = 23
tn = a + (n - 1) d
t23 = 9 + (23 - 1)(-5)
= 9 + 22 × -5
= 9 - 110
= -101
APPEARS IN
RELATED QUESTIONS
Find the sum of the following arithmetic series:
34 + 32 + 30 + ... + 10
Find the sum of the following arithmetic series:
(–5) + (–8) + (–11) + ... + (–230)
Find the 19th term of the following A.P.:
7, 13, 19, 25, ...
Find the 27th term of the following A.P.
9, 4, –1, –6, –11,...
Six year before, the age of mother was equal to the square of her son's age. Three year hence, her age will be thrice the age of her son then. Find the present ages of the mother and son.
Select the correct alternative and write it.
If a share is at premium, then -
How many multiples of 4 lie between 10 and 205?
Find tn if a = 20 and d = 3.
Find t5 if a = 3 and d = –3.
Decide whether the given sequence 24, 17, 10, 3,...... is an A.P.? If yes find its common term (tn).
Decide whether 301 is term of given sequence 5, 11, 17, 23,.....
Activity :- Here, d = `square`, therefore this sequence is an A.P.
a = 5, d = `square`
Let nth term of this A.P. be 301.
tn = a + (n – 1) `square`
301 = 5 + (n – 1) × `square`
301 = 6n – 1
n = `302/6` = `square`
But n is not positive integer.
Therefore, 301 is `square` the term of sequence 5, 11, 17, 23,......
12, 16, 20, 24,...... Find 25th term of this A.P.
The nth term of an A.P. 5, 8, 11, 14,...... is 68. Find n = ?
Find a and b so that the numbers a, 7, b, 23 are in A.P.
In an A.P. if the sum of third and seventh term is zero. Find its 5th term.
Write the next two terms of the A.P.: `sqrt(27), sqrt(48), sqrt(75)`......
