In this task, you need to answer the given multiple-choice question on geometry. Classify your answers into 'a', 'b', 'c', 'd', and 'e'.

Problem: in the xy - plane , a triangle has vertices ( 0,0 ) , ( 4,0 ) and ( 4,6 ) . if a point ( a , b ) is selected at random from the triangular region , what is the probability that a - b > 0 ? 
Options: a ) 1 / 5 , b ) 1 / 3 , c ) 1 / 2 , d ) 2 / 3 , e ) 4 / 5
d

Problem: find the perimeter of a triangle with sides measuring 7 centimeters , 10 centimeters and 15 centimeters . 
Options: ['a ) 10 cm', 'b ) 15 cm', 'c ) 32 cm', 'd ) 35 cm', 'e ) 20 cm']
c

Problem: what is the smallest positive integer x such that 108 x is the cube of a positive integer ? 
Options: a ) 2 , b ) 4 , c ) 8 , d ) 10 , e ) 7

a