# JEE Advanced 2015 Problem

**Algebra**Level 3

Suppose that all the terms of an arithmetic progression (AP) are positive integers. If the ratio of the sum of the first seven terms to the sum of the first eleven terms is 6 : 11, and the seventh term lies between 130 and 140, what is the common difference of this AP?

**Note**: This question was asked in JEE Advanced 2015.