Science:Math Exam Resources/Courses/MATH101 C/April 2024/Question 17 (b)/Solution 1

$${\begin{aligned}\mathrm {Pr} \left(-1\leq X\leq -{\frac {1}{4}}\right)\;\mathrm {d} x&=\int _{-1}^{-1/4}f(x)\;\mathrm {d} x=\int _{-1}^{-1/2}0\;\mathrm {d} x+\int _{-1/2}^{-1/4}1\;\mathrm {d} x=1/4.\end{aligned}}$$