Mr. Lawrence is building a fence around his vegetable garden which is in the shape of a rectangle with the length of 30 feet and width of 40 feet. Mr. Lawrence completed the fencing in 12 hours. What is the unit rate at which Mr. Lawrence put a fence around his vegetable garden?

11 2/3 feet per hour

Step-by-step explanation:

You add up the lengths to find the perimeter.

30 + 30 + 40 + 40 = 140

Then you divide the lengths by the amount of time taken

140/12 = 11 2/3 or 11 8/12 feet per hour

a 4/6 = 9/12   not proportional

step-by-step explanation:

to find which are not proportional, we can use cross products

if it is true, they are proportional.   if it is not true, they are not proportional.

a 4/6 = 9/12

4* 12 = 6*9

48 = 54

not this is not proportional  

b 2/3 = 12/18  

2* 18 = 3 * 12

36 = 36

this is proportional

c 5/4 = 10/8  

5*8 = 4*10

40 = 40

this is proportional

d 7/5 = 35/25

7*25 = 5 * 35

175 = 175

is proportional