Question

When the sum of the first ten terms of an A.P. is four times the sum of the first five terms. Then the kth term is​

Answer 1

Step-by-step explanation:

let a be the first term and d be the difference

according to question,

$\frac{10}{2} (2a + 9d) = 4 \times \frac{5}{2} (2a + 4d)$

$2(2 a+ 9 d)= 4(2a + 4d)$

$2 d= 4a$

$d = \: 2a$