Advertisements
Advertisements
प्रश्न
Find the sum of first 10 terms of the A.P.
4 + 6 + 8 + .............
Advertisements
उत्तर
Here,
First term, a = 4
Common difference, d = 6 – 4 = 2
n = 10
`S = n/2 [2a + (n - 1)d]`
= `10/2 [2(4) + 9(2)]`
= 5[8 + 18]
= 5 × 26
= 130
संबंधित प्रश्न
The sum of three numbers in A.P. is –3, and their product is 8. Find the numbers
In an AP given a = 8, an = 62, Sn = 210, find n and d.
Find the sum of all integers between 100 and 550, which are divisible by 9.
Find four numbers in AP whose sum is 28 and the sum of whose squares is 216.
Ramkali would need ₹1800 for admission fee and books etc., for her daughter to start going to school from next year. She saved ₹ 50 in the first month of this year and increased her monthly saving by ₹ 20. After a year, how much money will she save? Will she be able to fulfil her dream of sending her daughter to school?
Write the sum of first n even natural numbers.
If Sn denote the sum of the first n terms of an A.P. If S2n = 3Sn, then S3n : Sn is equal to
If a = 6 and d = 10, then find S10.
A merchant borrows ₹ 1000 and agrees to repay its interest ₹ 140 with principal in 12 monthly instalments. Each instalment being less than the preceding one by ₹ 10. Find the amount of the first instalment.
The first term of an AP is –5 and the last term is 45. If the sum of the terms of the AP is 120, then find the number of terms and the common difference.
