The Useful Life (In Years) of a Shingled Roof in Oregon

Multiple Choice

The useful life (in years) of a shingled roof in Oregon has a uniform distribution described by the probability density function below.What proportion of roofs have a useful life greater than 29 years? 1/10 for values of x between 25 and 35
F(x) =
0 everywhere else

A) .60
B) .55
C) .40
D) .50
E) .35