The three numbers are consecutive terms of a sequence.

MATHEMATICS · Multi-part · A Level · Mathematics · Sequences and series · Sequences and series

Problem

The three numbers

(2k-5),\; k,\; (k+7)

are consecutive terms of a sequence. (i) Check if they can form an arithmetic progression. If yes, find the value of

k

and the common difference. (ii) Check if they can form a geometric progression. If yes, find the value of

k

and the common ratio.