Question

Find four consecutive terms in an A.P. whose sum is -54 and the sum of the 1^st and the 3^rd terms is -30. 

Answer 1

Let the four consecutive terms be a –3d, a – d, a + d and a + 3d.

According to the first condition,

a – 3d + a – d + a + d + a + 3d = –54

\(\therefore\) The four consecutive of an A.P. terms are –18, –15, –12, –9.