Question 253104
Recall that {{{d=rt}}} which means that the distance is equal to the rate multiplied by time. Since he "runs 350 meters in 17 seconds", we can say that {{{d=350}}} and {{{t=17}}}. 



Plug these values in to get {{{350=r*17}}}. Now solve for 'r' to get {{{r=350/17=20.588}}}. So his average speed is about 20.588 meters per second. Note: this converts to about 46.05 mph, so either the book isn't being realistic or there's a typo somewhere.