ANS:B - 24
This is an A.P. in which a = 6, d = 6 and Sn = 1800
Then, |
n |
[2a + (n - 1)d] = 1800 |
2 |
|
n |
[2 x 6 + (n - 1) x 6] = 1800 |
2 |
3
n (
n + 1) = 1800
n(n + 1) = 600
n2 +
n - 600 = 0
n2 + 25
n - 24
n - 600 = 0
n(
n + 25) - 24(
n + 25) = 0
(
n + 25)(
n - 24) = 0
n = 24
Number of terms = 24.