In the given AP,
we have a = 13 , d = (8 - 13) = -5 and n = 10
Tn = a + (n - 1)d
T10 = 13 + (10 - 1) - 5
= 13 + 9 x (-5) = 13 - 45 = -32
In the given AP,
we have a = 3, d = (9 - 3) = 6, n =15
T15 = a + (n - 1)d
= 3 + (15 -1)6
= 3 + 84 = 87
Series pattern
12 x 1 + 3 x 1 = 15
15 x 2 + 3 x 2 = 36
36 x 3 + 3 x 3 = 117
Should come in place of ?
117 x 4 + 3 x 4 = 480
480 x 5 + 3 x 5 = 2415
2415 x 6 + 3 x 6 =14508
Series pattern
Previous number/5
? Missing term = 244/5 = 48.8
Series pattern
+ 13, + 26, + 39, + 52, + 65
? Missing term = 132 + 65 = 197
Series pattern
12, 32, 52, 72, 92, 112
So missing term = 112 = 121
We have, a = 10 , d = (8 - 10) = -2, Tn = - 28
Tn = a + (n - 1)d
? -28 = 10 + (n - 1) x (- 2)
? -28 = 10 - 2n + 2
? 2n = 12 + 28
? 2n = 40
? n = 20
T9 = a + (9 - 1)d = a + 8d
T5 = a + (5 - 1)d = a + 4d
T9 - T5 = 32
? (a + 8d) - (a + 4d) = 32
? 4d = 32
? d = 8
T9 + T5 = (a + 8d) + (a + 4d)
= 2a + 12d
T9 + T5 = 114
? 114 = 2(a + 6d)
? a + 6d = 57
? T8 = a + 7d
= a + 6d + d
= 57 + 8 = 65
This is an AP with a = 1 and d = 7
? 11th term = a + (n - 1) x d = 1 + (11 - 1) x 7
= 1 + 10 x 7 = 71
The first 100 terms of this series is
(1 - 2 - 3) + (2 - 3 - 4) + ... + (33 - 34 - 35) + 34
The first 33 terms of the above series will given an AP as
-4, -5, -6, ... -36
? Answer = 33 x (-20 ) + 34 = - 626
The least number between 200 and 400, which is divisible by 8 is 200. The last term less than 400, which is divisible by 8 is 400 .
? The series is 200, 208, 216,... , 400.
The number of terms in the AP is
(400 - 200/ 8) + 1 = 26
n = 26
d = 8
? Sum = n/2[2a + (n - 1) d]
= 26/2 [2x 200 + (26 -1) x 8]
= 13[400 + 200] = 7800
Comments
There are no comments.Copyright ©CuriousTab. All rights reserved.