The sum of first 6 terms of an arithmetic progression is 42. The ratio of its 10th term to its 30th term is `1:3`. Calculate the first and 13th term of an AP.

Explanation

Given,

`S_6 =42`

and,


`a_(10)=a + 9d ->(i)`

`a_(30)=a + 29d->(ii)`

Thus,

`(i)/(ii)=1/3`

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