Advertisements
Advertisements
Question
Find the sum of the following
102, 97, 92, … up to 27 terms.
Solution
Here a = 102, d = 97 – 102 = – 5
n = 27
Sn = `"n"/2` [2a + (n – 1)d]
S27 = `27/2` [2(102) + 26(– 5)]
= `27/2` [204 – 130]
= `27/2` × 74
= 27 × 37 = 999
S27 = 999
APPEARS IN
RELATED QUESTIONS
Find the sum of the following
6 + 13 + 20 + .... + 97
How many consecutive odd integers beginning with 5 will sum to 480?
The 104th term and 4th term of an A.P. are 125 and 0. Find the sum of first 35 terms
Find the sum of all odd positive integers less than 450
Raghu wish to buy a laptop. He can buy it by paying ₹ 40,000 cash or by giving it in 10 installments as ₹ 4800 in the first month, ₹ 4750 in the second month, ₹ 4700 in the third month and so on. If he pays the money in this fashion, find total amount paid in 10 installments
A brick staircase has a total of 30 steps. The bottom step requires 100 bricks. Each successive step requires two bricks less than the previous step
How many bricks are required for the top most step?
A brick staircase has a total of 30 steps. The bottom step requires 100 bricks. Each successive step requires two bricks less than the previous step
How many bricks are required to build the stair case?
An A.P. consists of 31 terms. If its 16th term is m, then the sum of all the terms of this A.P. is
In an A.P., the first term is 1 and the common difference is 4. How many terms of the A.P. must be taken for their sum to be equal to 120?
If A = 265 and B = 264 + 263 + 262 …. + 20 identify of the following is true?
