For an Arithmetic Progression (AP), the sum of first four terms and first eight terms is 288. If the sum of first twelve terms is 480, then what is the sum of first 15 terms of this AP?
First and last term of a geometric progression are 3 and 96. If the sum of all these terms is 189, then find the number of terms in this progression.
The sequence k, k^2, 16, k^3 has four terms in which first three terms are in GP. What should be added in fourth term to get the last 3 terms in AP ?
