Question

Sum of the first p, q and r terms of an A.P. are a, b and c, respectively.

Answer 1

Let a1 and d be the first term and the common difference of the A.P. respectively.
According to the given information,

Subtracting (2) from (1), we obtain

Subtracting (3) from (2), we obtain

Equating both the values of d obtained in (4) and (5), we obtain