1. a denominator is the both number in a fraction. 5 times what number equals 55? multiply 3 by that number, and that's what you put in your numerator of your new fraction!
[your answer should come out to 33/55.]
2. well, let's set up fractions! instead of miles per hour, let's do rides per hour! so, we have 1 ride/2.5 hours. then we have x rides/40 hours. now we just set them equal. so:
1/2.5 = x/40
40 = 2.5x
x = 16
16 rides repaired in 40 hours.
i don't know how to insert long division into html or i'd help you with the next two also. it's just long division, though. you can probably google examples and base yours off that.