Aptitude Knowledge Question: If 20% of a = b, then b% of 20 is the same as: A. 4% of a B. 5% of a C. 20% of a D. None of these Aptitude Knowledge Interview QuestionAnswer: A. 4% of a Previous QuestionNext Question3 pumps, working 8 hours a day, can empty a tank in 2 days. How many hours a day must 4 pumps work to empty the tank in 1 day? A. 9 B. 10 C. 11 D. 12A motorboat, whose speed in 15 km/hr in still water goes 30 km downstream and comes back in a total of 4 hours 30 minutes. The speed of the stream (in km/hr) is: A. 4 B. 5 C. 6 D. 10