How do I find the probability for this question?

Question

Hi, if someone could help me solve this problem that would be great, thank you

"A distribution is given as X ~ U(0, 12)."

Find P(x > 9).  (Enter an exact number as an integer, fraction, or decimal.)

Answer 1

U (0,12) is a uniform distribution from x=0 to x = 12.

If you plot the pdf it will have width 12 and height (1/12) - the area under it must be 1.

p(x>9) is area of pdf from x = 9 to x = 12 = 3 x (1/12) = 3/12 = 1/4 = 0.25