A rower can row upstream at 7 km/hr and downstream at 15 km/hr. What is the rower's rate in still water?
Choices
A) 9 km/hr	B) 10 km/hr	C) 11 km/hr	D) 12 km/hr	E) 13 km/hr
The rate in still water is 1/2 * (15 + 7)= 
<gadget id="calculator">1/2 * (15 + 7)</gadget>
<output>11</output>
11 km/hr   The answer is 11 km/hr.
<result>C</result>
A rower can row upstream at 7 km/hr and downstream at 15 km/hr. What is the rower's rate in still water?