Question

The 4th term of an A.P. is three times the first and the 7th term exceeds twice the third term by four. Find the first term and the common difference.

Answer 1

Let the A.P be -`a,a+d,a+2d............`
according to the question,`a+3d=3a`...(1) and `a+6d=2(a+2d)+4`....(2)
From (1) and(2) `d=8 `and `a=12`
the A.P is `12,20,28,36,44........`