Finding total area and probability?

(A)
f(0) = 2/3 , so the y-intercept = 2/3
(2/3) - (2/9)x = 0 , x = 3 , so the x-intercept = 3

total area beneath f(x) for 0 ≤ x ≤3
= (1/2)*3*(2/3)
= 1 ..... Ans

(B)
P( 0.5 ≤ x ≤ 1.5 )
= ∫ [ (2/3) - (2/9)x ] dx , from x = 0.5 to x = 1.5
= [ 2x/3 - x^2/9 ] , from x = 0.5 to x = 1.5
= [ 2*1.5/3 - 1.5^2/9 ] - [ 2*0.5/3 - 0.5^2/9 ]
= 4/9 ..... Ans

Finding Total Area