Find the number of terms and the sum of the terms of the arithmetic progressions 32,28,….4a.14 : 252b.8 : 144c.15 : 270d.7 : 126
Question
Find the number of terms and the sum of the terms of the arithmetic progressions 32, 28, …. 4
Options:
- 14 : 252
- 8 : 144
- 15 : 270
- 7 : 126
Solution
Sure, let's solve this step by step:
a. 32, 28, …, 4
The common difference (d) here is 28 - 32 = -4. The first term (a) is 32 and the last term (l) is 4.
The number of terms (n) in an arithmetic progression can be found using the formula: n = [(l - a) / d] + 1
So, n = [(4 - 32) / -4] + 1 = 8
The sum (S) of an arithmetic progression can be found using the formula: S = n/2 * (a + l)
So, S = 8/2 * (32 + 4) = 144
b. 14 : 252
Here, a = 14, l = 252, and d = 252 - 14 = 238
So, n = [(252 - 14) / 238] + 1 = 2
And, S = 2/2 * (14 + 252) = 133
c. 8 : 144
Here, a = 8, l = 144, and d = 144 - 8 = 136
So, n = [(144 - 8) / 136] + 1 = 2
And, S = 2/2 * (8 + 144) = 76
d. 15 : 270
Here, a = 15, l = 270, and d = 270 - 15 = 255
So, n = [(270 - 15) / 255] + 1 = 2
And, S = 2/2 * (15 + 270) = 142.5
e. 7 : 126
Here, a = 7, l = 126, and d = 126 - 7 = 119
So, n = [(126 - 7) / 119] + 1 = 2
And, S = 2/2 * (7 + 126) = 66.5
Please note that the calculations for b, c, d, and e assume that the common difference is the difference between the two given terms, which may not be the case if there are other terms in between.
Similar Questions
Determine the 30th term in an arithmetic sequence {8, 17, 26, 35 …}Also find their associated sum.
Find the 10th term of the arithmetic progression whose 4th term is 7 and whose 17th term is 72.a.42b.47c.32d.37
If the sum of the first 11 terms of an arithmetic progression equals that of the first 19 terms, then what is the sum of the first 30 terms?
Find the sum of the first 20 terms of an arithmetic progression, if its fifth term is 11 and its 16th term is 39.
Find the 22nd term of the arithmetic progression whose first term is 20 and common difference is 1/3.a.27 2/3b.27c.27 1/3d.28
Upgrade your grade with Knowee
Get personalized homework help. Review tough concepts in more detail, or go deeper into your topic by exploring other relevant questions.