### Home > PC > Chapter 10 > Lesson 10.1.3 > Problem10-41

10-41.

The current in a straight river is flowing so that if a motorboat travels upstream at an angle of $20°$ with a velocity of $15$ km/hr, it will land at a spot on the opposite shore directly opposite its starting point. Find the speed of the current.

Draw a diagram.

Use trigonometry to solve for the 'current'.