Question

the sum of first six terms of an A.P. is 42. the ratio of the 10th term to the 30th term is 1:3. find first term and 11th term of the A.P​

Answer 1

Answer:

1st term(a) = 7/3

11th term = 77/3

Step-by-step explanation:

sum of 1st 6 terms => 42 = 6\2[a + 5d] => a+5d = 14 --- eq.(1)

ratio of 10th and 30th terms => (a+9d)/(a+29d) = 1/3 => a= d --- eq.(2)

From eq. (1) &(2)

6a = 14

a = 7/3 => 1st term

11th term = a + 10d = 11a = 77/3