Advertisements
Advertisements
प्रश्न
Which term of an A.P. 16, 11, 6, 1, ... is – 54?
उत्तर
A.P. = 16, 11, 6, 1, ...
It is given that
tn = – 54
a = 16, d = t2 – t1 = 11 – 16 = – 5
∴ tn = a + (n – 1)d
– 54 = 16 + (n – 1)(– 5)
– 54 = 16 – 5n + 5
21 – 5n = – 54
– 5n = – 54 – 21
– 5n = – 75
n = `75/5` = 15
∴ 15th term is – 54.
APPEARS IN
संबंधित प्रश्न
In the following situation, involved make an arithmetic progression? and why?
The amount of money in the account every year, when ₹ 10000 is deposited at compound interest at 8% per annum.
Find a30 − a20 for the A.P.
a,a + d, a + 2d, a + 3d, ...
How many three digit numbers are divisible by 7?
First term a and common difference d are given below. Find the corresponding A.P.
a = 5, d = 6
If 6 times of 6th term of an A.P. is equal to 7 times the 7th term, then the 13th term of the A.P. is
For an A.P., t4 = 12 and its common difference d = – 10, then find tn
Which of the following form an AP? Justify your answer.
`1/2, 1/3, 1/4, ...`
In which of the following situations, do the lists of numbers involved form an AP? Give reasons for your answers.
The fee charged from a student every month by a school for the whole session, when the monthly fee is Rs 400.
Which of the following form an AP? Justify your answer.
`sqrt(3), sqrt(12), sqrt(27), sqrt(48)`
First term and common difference of an A.P. are 1 and 2 respectively; find S10.
Given: a = 1, d = 2
find S10 = ?
Sn = `n/2 [2a + (n - 1) square]`
S10 = `10/2 [2 xx 1 + (10 - 1)square]`
= `10/2[2 + 9 xx square]`
= `10/2 [2 + square]`
= `10/2 xx square = square`
