A man's speed with the current is 21 km/hr and the speed of the current is 2.5 km/hr. The man's speed against the current is?	Choose one
A) 10  B) 20  C) 16  D) 30  E) 40

Rationale: "man ' s speed with the current = 21 km / hr = > speed of the man + speed of the current = 21 km / hr speed of the current is 2.5 km / hr hence , speed of the man = 21 - 2.5 = 18.5 km / hr man ' s speed against the current = speed of the man - speed of the current = 18.5 - 2.5 = 16 km / hr answer is c ."
Answer: C