question_answer

  Let u be speed of rowing in still water and v be the speed of current. and         speed of rowing in still water = 6 km/hr and speed of current = 4 km/hr. OR Let u be speed of rowing in still water and v be the speed of current. and         speed of rowing in still water = 6 km/hr and speed of current = 4 km/hr.

Answer:

  Ritu can row downstream 20 km in 2 hrs. and upstream 4 km in 2 hrs. Find the speed of rowing in still water and the speed of the current OR In a competitive examination, one mark is awarded for each correct answer while  mark is deducted for each wrong answer. Sheela answered 120 questions and got 90 marks. How many questions did she answer correctly?