Advertisements
Advertisements
प्रश्न
Write the formula of the sum of first n terms for an A.P.
Advertisements
उत्तर
Sum of the first n terms is given by
Sn = `"n"/2[2"a" + ("n" - 1)"d"]`,
where a = first term,
d = common difference
OR
Sn = `"n"/2("t"_1 + "t"_"n")`,
where t1 = first term,
tn = last term
APPEARS IN
संबंधित प्रश्न
In an AP Given a12 = 37, d = 3, find a and S12.
The sum of the third and the seventh terms of an AP is 6 and their product is 8. Find the sum of first sixteen terms of the AP.
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.
If `4/5 `, a, 2 are in AP, find the value of a.
Find the sum of the following Aps:
i) 2, 7, 12, 17, ……. to 19 terms .
How many terms of the AP `20, 19 1/3 , 18 2/3, ...` must be taken so that their sum is 300? Explain the double answer.
Write an A.P. whose first term is a and the common difference is d in the following.
a = 10, d = 5
If the 9th term of an A.P. is zero then show that the 29th term is twice the 19th term?
The sum of the first n terms of an A.P. is 3n2 + 6n. Find the nth term of this A.P.
The sum of first n terms of an A.P. is 3n2 + 4n. Find the 25th term of this A.P.
Write 5th term from the end of the A.P. 3, 5, 7, 9, ..., 201.
Q.6
Q.13
Q.15
In a Arithmetic Progression (A.P.) the fourth and sixth terms are 8 and 14 respectively. Find that:
(i) first term
(ii) common difference
(iii) sum of the first 20 terms.
If ₹ 3900 will have to be repaid in 12 monthly instalments such that each instalment being more than the preceding one by ₹ 10, then find the amount of the first and last instalment
Find the sum of first 'n' even natural numbers.
In the month of April to June 2022, the exports of passenger cars from India increased by 26% in the corresponding quarter of 2021-22, as per a report. A car manufacturing company planned to produce 1800 cars in 4th year and 2600 cars in 8th year. Assuming that the production increases uniformly by a fixed number every year. |
Based on the above information answer the following questions.
- Find the production in the 1st year
- Find the production in the 12th year.
- Find the total production in first 10 years.
[OR]
In how many years will the total production reach 31200 cars?
Find the sum of all 11 terms of an A.P. whose 6th term is 30.
k + 2, 2k + 7 and 4k + 12 are the first three terms of an A.P. The first term of this A.P. is ______.
