A Random Variable X Has a Cumulative Distribution Function F(x) $\frac { x } { 5 }$

Short Answer

A random variable X has a cumulative distribution function F(x) = $\frac { x } { 5 }$ - 2, $10 \leq x \leq 15$ . Find a such that $\operatorname { Pr } ( a \leq X \leq 15 ) = \frac { 2 } { 3 }$ Enter just a reduced fraction of form $\frac { a } { b }$ .