Iknow this should be easy but i don't understand it

If 10 men take 18 days to mow 60 acres of grass, how long will 15 men take to mow 80 acres?

If you have a set of parallel lines a and b cut by transversal x, if angle 1 = 167 degrees, what is angle 4 and why. also what is the measure of angle 5 and why? you need to use the names of the angle relationship and explain.

If x+y+z=0 what is the value of [tex] {x}^{3} + {y}^{3} + {z}^{3} [/tex]