Directions: Answer the questions based on the information given below.
There are four trains 'A', 'B', 'C', and 'D' which cover certain distances with certain speeds. Each train's distance, time, and speed is in km, min, and km/hr respectively.
(1) Distance travelled and time taken by train 'A' when travelling with speed 'X' km/hr is (a, a + 15) respectively.
(2) The speed of train 'B' and the time taken by it to cover 'Y' km distance is (2b + 8, b) respectively.
(3) Distance travelled and time taken by train 'C' when travelling with speed 'c+5' km/hr is (c, 50) respectively.
(4) Distance travelled and time taken by train 'D' when travelling with speed '4d' km/hr is (d, 2d - 15) respectively.
Some additional information is also known :
(i) P = Smallest roots of 2x2 - 19x + 44 = 0
(ii) Q = Value of 'q' in 3P2 - 2q = 44
(iii) R = Largest single-digit prime number
(iv) X - 7 = R2 - 4P