The best way to do this is to draw a picture of ΔFKL and include line segment KM that is perpendicular to FL. This creates ΔFKM which is a 45°-45°-90° triangle and ΔLKM which is a 30°-60°-90° triangle.
Find the lengths of FM and ML. Then, FM + ML = FL
<u>FM</u>
ΔFKM (45°-45°-90°): FK is the hypotenuse so FM =
<u>ML</u>
ΔLKM (30°-60°-90°): from ΔFKM, we know that KM =
, so KL =
<u>FM + ML = FL</u>

= 
In a rhombus, all sides are equal:
5x = 15
and x = 15/5 = 3
(you could have done the same thing with the other side: 5x = 4x +3)
The 105 per hour mechanic worked for 10 hours and the other worked for 15. here's the math.
Basically it’s r=c/2pi meaning it’d be r=62/2(3.14) which would give you r=9.87
Since k is constant (the same for every point), we can find k when given any point by dividing the y-coordinate by the x-coordinate.