Advertisements
Advertisements
प्रश्न
Find tn if a = 20 and d = 3.
Advertisements
उत्तर
tn = a + (n – 1)d
= 20 + (n – 1)3
= 20 + 3n – 3
= 17 + 3n
APPEARS IN
संबंधित प्रश्न
If the 9th term of an A.P. is zero, then prove that 29th term is double of 19th term.
Find the sum of the following arithmetic series:
`7 + 10 1/2 + 14 + ... + 84`
Find the sum of the following arithmetic series:
34 + 32 + 30 + ... + 10
Find the sum of the following arithmetic series:
(–5) + (–8) + (–11) + ... + (–230)
Decide whether the following sequence is an A.P., if so find the 20th term of the progression:
–12, –5, 2, 9, 16, 23, 30, ..............
Find the 27th term of the following A.P.
9, 4, –1, –6, –11,...
If the sum of first n terms of an AP is n2, then find its 10th term.
How many multiples of 4 lie between 10 and 205?
If third term and fifth term of an A.P. are 13 and 25 respectively, find its 7th term.
Find t5 if a = 3 and d = –3.
How many two-digit numbers are divisible by 5?
Activity :- Two-digit numbers divisible by 5 are, 10, 15, 20, ......, 95.
Here, d = 5, therefore this sequence is an A.P.
Here, a = 10, d = 5, tn = 95, n = ?
tn = a + (n – 1) `square`
`square` = 10 + (n – 1) × 5
`square` = (n – 1) × 5
`square` = (n – 1)
Therefore n = `square`
There are `square` two-digit numbers divisible by 5.
12, 16, 20, 24,...... Find 25th term of this A.P.
If tn = 2n – 5 is the nth term of an A.P., then find its first five terms.
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.
Write the next two terms of the A.P.: `sqrt(27), sqrt(48), sqrt(75)`......
