SBI PO 07 May 2017 Papers

Total distance between A and B is d km. The distance travelled along the stream is three times of the total distance and the distance travelled against the stream is two times of the total distance. The time taken to cover distance along the stream is 10% less than the time taken to cover the distance against the stream. If a person covers a distance of 21 km in 1 hour 24 minutes along the stream, then find the rate of current?