A start walking from a place at a uniform speed of 5 kmph in a particular direction. After half an hour, B starts from the same place and walks in the same direction as A at a uniform speed and overtakes A after 1 hour 48 minutes. Find the speed of B. Choose the correct choice from the following options:
A) 4.7 kmph
B) 5.6 kmph
C) 4 kmph
D) 7 kmph
E) 5.3 kmph

Rationale: "distance covered by a in 30 min = 1 km b covers extra 1 km in 1 hour 48 minutes ( 9 / 5 hr ) i . e . relative speed of b over a = 1 / ( 9 / 5 ) = 5 / 9 so the speed of b = speed of a + 5 / 9 = 5 + 5 / 9 = 5.55 answer b"
Answer: B