John swims in a river at an effective speed of 8 Kilometers/hr. The velocity of the stream against John is measured to be 2 Kilometers/hr. Now, how much his effective speed will increase when he swims in the direction of the stream.

• Since John opposes the stream speed to achieve an effective speed of 8 Km/hr, original physical speed of John would be 8 + 2 = 10 Kilometers/hr. In downstream, if he swims with his original speed his effective speed will become 10 + 2 = 12 Kilometers/hr. This is 4 Kilometers/hr more than that of the initial effective speed 8 Kilometers/hr.
  
  Hence his speed would increase by 4/8 % = 50%.
• 12 years agoHelpfull: Yes(9) No(2)