Answer: B) 9 km/hr, 3 km/hr Explanation: Let the speed of the boat = p kmph Let the speed of the river flow = q kmph From the given data, 2 x 28p + q = 28p - q   => 56p - 56q -28p - 28q = 0 => 28p = 84q => p = 3q. Now, given that if 283q + 2q + 283q - 2q = 67260=> 285q + 28q = 67260=> q = 3 kmph=> x  =3q = 9 kmph   Hence, the speed of the boat = p kmph = 9 kmph and the speed of the river flow = q kmph = 3 kmph.

Answer: D) Intellectual Explanation: The one word substitute for A person of good understanding knowledge and Reasoning power is Intellectual.