The ratio 30 in. to 9ft in simplest form

Convert "inches" to "feet" here.     30 in        1 ft            30
                                                      = =  ft
                                                          1          12 in           12

Now find the ratio of (30 ft / 12) to 9 ft:

30 ft
 
  12           30
  =    Reduce this fraction; one way would be to
 9 ft          12(9)       write 30/9 as 10/3:

  30            10
= = 5/18 (answer)
12(9)       12(3)