Advertisements
Advertisements
प्रश्न
Find the sum of the first 22 terms of the A.P. : 8, 3, –2, ………
Advertisements
उत्तर
The given A.P. is 8, 3, –2, ………
Here, a = 8, d = 3 – 8 = –5 and n = 22
∴ `S = n/2[2a + (n - 1)d]`
= `22/2 [2 xx 8 + (22 - 1) xx (-5)]`
= 11[16 + 21 × (–5)]
= 11[16 – 105]
= 11 × (–89)
= –979
APPEARS IN
संबंधित प्रश्न
How many terms of the A.P. : 24, 21, 18, ................ must be taken so that their sum is 78?
Find the sum of first 12 natural numbers each of which is a multiple of 7.
Determine k so that (3k -2), (4k – 6) and (k +2) are three consecutive terms of an AP.
Divide 24 in three parts such that they are in AP and their product is 440.
The next term of the A.P. \[\sqrt{7}, \sqrt{28}, \sqrt{63}\] is ______.
A man is employed to count Rs 10710. He counts at the rate of Rs 180 per minute for half an hour. After this he counts at the rate of Rs 3 less every minute than the preceding minute. Find the time taken by him to count the entire amount.
If the sum of first p term of an A.P. is ap2 + bp, find its common difference.
If 18, a, b, −3 are in A.P., the a + b =
The sum of first 15 terms of an A.P. is 750 and its first term is 15. Find its 20th term.
If the third term of an A.P. is 1 and 6th term is – 11, find the sum of its first 32 terms.
