Question 173601
In Sunday's 15 mile paddle-board race, after 6 miles, Kongo saw that he was
 1/2 a mile behind his friend Kimo, whose speed was 6mph. 
At what rate did Kongo paddle, if he caught his friend exactly at the finish line?
:
From the given information we know:
Ko has to travel (15-6) 9 mi,
 while
Ki has to travel (15-6.5) 8.5 mi
:
Let s = Ko's speed required to catch Ki at the finish line
:
Write a time equation; Time = (dist/speed)
:
Ko's time = Ki's time
{{{9/s}}} = {{{8.5/6}}}
Cross multiply
8.5s = 9 * 6
:
8.5s = 54
s = {{{54/8.5}}}
s = 6.353 mph Ko's speed required to accomplish this
;
:
Check solution by finding that the travel times are equal
9/6.353 = 1.41 hrs
8.5/6 = 1.41 hrs also