solution for 10b
as someone said before, graph it and P = 1 - (areas of triangles)
for the last part, you need to express the areas in terms of t.
This is 1/2 (1-t)^2
since there are two trinalges, P = 1 - (1-t)^2
form a quadratic, solve it with the formula, and since t < 1, you...